Champions League Power Rankings: Who is the most in-form team?

Roma's start to the season has been far from straight forward. Despite an opening-day victory against Torino, the capital club have failed to pick up a victory in their other three Serie A fixtures, losing 2-1 against AC Milan in their previous away game. Roma also went down to Serie B side Benevento in a friendly game during the recent international break.

A trip to Real Madrid to start their Champions League campaign will be an enormous challenge, though their exploits against Barcelona in the competition last season may give them hope.

Monaco find themselves just a point outside the bottom two in the Ligue 1 table after five games and without a win in their last four.

Radamel Falcao and Co. have been grouped with Borussia Dortmund, Club Brugge and Atletico Madrid, who visit on Tuesday, and face a tough task to turn their fortunes around in the next game.

Tipped as Juventus' main contenders in Serie A, Inter have struggled to live up to expectations thus far in Italy after a busy summer of transfers.

Defeats to Torino and Parma have left them in the lower reaches of the table, and with Barcelona, Tottenham and PSV to come in the Champions League, Luciano Spalletti needs to find a winning formula quickly.

Valencia's only victory this season came in a friendly against second-division CD Alcoyano, highlighting the club's struggles so far this season.

Though they finished fourth last season, Valencia have managed three draws and a defeat in their opening four Liga outings, with a 1-1 draw at home to Atletico Madrid a rather unremarkable standout result.

Cristiano Ronaldo's return to Spain is the stuff of nightmares for the Liga outfit, with the Juventus forward finally opening his account for his new club at the weekend.

Expectations around Schalke's Bundesliga season jumped a little when they beat Fiorentina in their final pre-season friendly. A simple cup victory against Schweinfurt has been followed by three consecutive losses in the league, however, and they find themselves joint-bottom of the German top-tier with Bayer Leverkusen.

A meeting with Porto on Tuesday will provide Schalke with a distraction from a difficult start to the season, if nothing else.

Atletico Madrid's season got off to a perfect start as Diego Simeone's side got the better of rivals Real Madrid in the UEFA Super Cup final.

Since then, however, Atletico have struggled to keep pace with Real and leaders Barcelona, dropping points against Valencia, Rayo Vallecano, and losing to Celta Vigo.

Tuesday's visit to Monaco is set to be a difficult one for the Madrid outfit.

Hoffenheim games are rarely without goals, and each of their last five games have seen both team score. Unfortunately for the Bundesliga side, however, two of their first three results have gone against them, both away from home.

Another game away from Rhein-Neckar-Arena awaits, too, with Shakhtar Donetsk this week's opponents in Europe.

The Champions League draw was kind to Lokomotiv, with Schalke, Porto and Galatasaray making up a group that they'd have accepted ahead of when they were decided.

Lokomotiv find themselves woefully out of form, however, picking up two wins in their last five games and placed 10th in the Russian Premier League.

Lyon's start to the Ligue 1 season has been a mixed one, with two wins and two draws coming in their first five outings.

Memphis Depay is the only player to have scored more than one goal, however, which is a cause of concern as they travel to free-scoring Manchester City for their opening Champions League tie.

Tensions have eased slightly at Manchester United following consecutive victories; Jose Mourinho's side have beaten both Burnley and Watford away from home following the club's worst start to a season in 26 years.

United have already lost to Brighton and Tottenham this season but come into their tie against Young Boys in relatively healthy shape and will be confident of a third straight win on the road.

Although Tottenham's season started as well as they could have hoped, with wins coming against Newcastle, Fulham and Manchester United, defeats against Watford and Liverpool have left Spurs with ground to make up.

A trip to Inter offers a break from domestic football against a side who are struggling to find momentum at present, winning just one of their opening four Serie A games.

Life after Maurizio Sarri has proved no problem for Napoli so far. The Serie A side have three victories in their opening four games, with Lazio and AC Milan already taken care of.

A defeat away at Sampdoria sees them behind only Juventus in the Serie A table at present, while a friendly loss against Wolfsburg is the only other red mark against their name from their last five games.

A new manager, a new era. Julen Lopetegui was forced to build his new side without Cristiano Ronaldo this season and was immediately under pressure following a 4-2 Super Cup loss to city rivals Atletico prior to the start of the new Liga campaign.

Since then, however, Real have won three and drawn one of their four league outings, with Karim Benzema and Gareth Bale making up for the goals lost to Ronaldo's summer exit. A victory over Roma in the Champions League would be a welcome addition to what has been a relatively succesful opening to 2018-19.

Last season's champions Porto have started their season with three wins from four league games, scoring 13 goals in the process.

They go into their Champions League tie against Schalke as favourties, too, as the Bundesliga outfit continue struggle on a domestic front.

Benfica remain unbeaten after the first four league games of the season and have won their past two away games to nil.

Their home performances have been slightly less impressive, though the visit of Bayern Munich this week may add a spring to the Portuguese side's step.

CSKA Moscow's meeting with Viktoria Plzen won't be one to steal the headlines, but it sees two in-form teams fight it out for a chance to sneak through into the knockout rounds of the competition in place of favourites Real Madrid and Roma.

CSKA's last three wins have been to nil, though their form away from home has been far from convincing and Wednesday's trip to Doosan Arena could prove an early blow to their European hopes.

Plzen's chances of a title took a hit at the start of the month as Slavia Prague handed out a humiliating 4-0 thrashing, though a narrow 1-0 win over Opava saw Pavel Vrba's men put the Czech side back on track. 

Plzen host CSKA for their opening Champions League tie before clashes with Roma and Real Madrid, adding weight to the importance of claiming points this week.

Super Lig leaders Galatasaray have scored 11 goals in their last four fixtures, albeit with a 4-0 defeat to Trabzonspor sandwiched in between. 

They re-claimed the league title last season and look good value to do the same this time round, while European success also looks attainable with a group of Schalke, Porto and Tuesday's opponents Lokomotiv standing in their way.

Though there is plenty of room for improvement, Juventus have opened the 2018-19 Serie A season with four wins from four, the latest of which marked Cristiano Ronaldo's first goals for the club since his summer switch from Real Madrid.

They travel to Valencia ahead of Wednesday's Champions League tie with only an International Champions Cup loss to their name from their last five outings, though the 3-1 defeat means almost nothing as the Old Lady look to kick their European campaign off with three points.

It's a case of so far, so good for Lucien Favre's Borussia Dortmund. 

A 4-1 home win over RB Leipzig kick the season off and was followed by a 6-0 DFB-Pokal rout over Osnabruk, with a 3-1 win against Eintracht Frankfurt their latest result. A 0-0 draw with Hannover is all that keeps them from matching Bayern Munich's start to the season, with Club Brugge the opposition in their first Champions League game of the season.

Ajax's last three Eredivisie serve as a reminder to AEK Athens, Bayern Munich and Benfica that the Dutch side are a threat to their qualification to the next round.

The Amsterdam club beat Groningen 3-0, Vitesse 4-0, and FC Emmen 5-0 as they look to get their hands back on the Eredivisie title and come into the Champions League matchday full of confidence.

Manchester City have picked up where they left off last season, though will be frustrated at dropping points against Wolves in the third weekend of the 2018-19 season.

City have picked up four wins from their opening five fixtures, however, with only Chelsea and Liverpool ahead of them in the rankings. From their three home games this season, City have picked up nine points, scored 11 goals and conceded just two and go into their clash with Lyon as firm favourites.

Nineteen points from seven games is enough to see Club Brugge enter the first round of Champions League games as leaders of the Belgian First Division.

While a European clash against Borussia Dortmund is a far greater task than what they've faced so far this season, the Belgian champions go into the tie full of expectation.

Three wins from three Super League games sees AEK joint top of the Greek league, with an additional victory coming in a friendly clash with Trikala.

Marinos Ouzounidis' side take on Ajax in their opening game, one of the form teams in the competition, before home games against Bayern Munich and Benfica.

Last season's Eredivisie champions have again been the team to catch so far this time round, winning five from five and scoring 21 goals.

Mark van Bommel returns to Barcelona in the Champions League with his side top of the Dutch top flight, fresh from a 7-0 victory over Den Haag.

Eight matches into the Ukrainian Premier League and Shakhtar Donetsk are already five points clear of second place.

Their only defeat this term came at the hands of Dynamo Kyiv, though five successive victories have put that loss right and they stand in good stead going into their European tie against Hoffenheim.

Young Boys face a baptism of fire in Europe this season, with ties against Manchester United, Juventus and Valencia all to come.

Their league form suggests that the Swiss side will at least make life difficult for their opponents despite odds being heavily against them to progress in the competition. It's six wins from six so far this season for Young Boys, with a goal difference of +15.

Red Star have proved by far and away the strongest side in the Serbian top-tier this season, winning all seven of their league games with a positive goal difference of 19.

Unfortunately for the league leaders, though, they've been drawn against Liverpool, Paris Saint-Germain and Napoli, who they kick their European campaign off with this week.

Despite starting life under a new regime, Niko Kovac's side have had no problems in their early Bundesliga fixtures so far. The Bavarian side are three from three in the German top flight, with victories over the Chicago Fire and SV Drochtersen/Assel to boot.

This week's trip to Benfica will prove Bayern's toughest test so far, however, and will set the tone for what should be an easy group for the German champions.

Paris Saint-Germain have blitzed each team that has come up against them this season, with Thomas Tuchel breaking the record for his perfect start as manager of the Parisian club.

PSG have five wins from five, with Neymar and Kylian Mbappe both already on four goals each, while Edinson Cavani has three. The deadly front three will go up against another in-form attacking trio in Mohamed Salah, Roberto Firmino and Sadio Mane in the Champions League clash in a battle that will go some way to settling which of the two top the group.

Five Premier League games, five victories. Jurgen Klopp's men were widely tipped to be Manchester City's main challengers for the top-flight title this season and have opened the new season in perfect form.

The Reds have recored back-to-back 2-1 away victories, against Leicester and Tottenham, following wins against Brighton, Crystal Palace and West Ham. 

To little surprise, Barcelona have won all four of their La Liga fixtures this season and sit top of the Spanish league with a goal difference of +11. 

Barca's 3-0 friendly victory over Boca Juniors in their final outing before the season suggested a positive start to Liga life was on the cards, and Lionel Messi and Co. have certainly enjoyed the early stages of the campaign so far.

PSV are the visitors this week, with the Eredivisie side also enjoying 2018-19, sitting top of their leaugue and fresh from a 7-0 win over OD Den Haag.