Andrea Berta was cooking this summer: Premier League winners and losers as Arsenal new boys lead the way while late-window arrivals Nick Woltemade and Alejandro Garnacho enjoy contrasting debuts

Given the way Liverpool splashed the cash over the summer, it went a little under the radar just how much Arsenal forked out in Andrea Berta's first window as sporting director. Only five European clubs have ever spent more than the Gunners' £255 million ($345.7m) outlay in a single summer, with eight new faces now available to Mikel Arteta as he looks to end his five-year trophy drought.

And while Arsenal returned to action against Nottingham Forest on Saturday still licking their wounds from their defeat at Anfield before the international break, Saturday's 3-0 win at the Emirates Stadium was a perfect illustration of the quality and depth Berta has added to Arteta's squad.

All three goals were scored by summer signings - two for Martin Zubimendi and one for Viktor Gyokeres - while Eberechi Eze marked his full debut with a fine assist. Cristhian Mosquera also stepped into William Saliba's shoes at the heart of defence and looked like he'd been doing it all his life, but the best performer on the day was Noni Madueke, who ran Forest ragged down the right-hand side with an electric showing.

Last season, the thought of Arsenal running out comfortable winners despite Saliba, Bukayo Saka and Declan Rice all being out of the line up while Martin Odegaard was forced off with a first-half injury would have been almost unthinkable. However, the money spent by the Gunners and the quality added by Berta is already paying dividends. 

Ironically, despite Liverpool sitting atop the table with four wins out of four, their own raft of summer signings are - Hugo Ekitike aside - yet to make that much of an impact on Arne Slot's side. Florian Wirtz has shown glimpses of his brilliance without yet unlocking a Premier League defence, while injury has limited Jeremie Frimpong's impact thus far. Alexander Isak, meanwhile, is still waiting for his debut after being left out of the squad for Sunday's trip to Burnley as he works his way up to match fitness.

Perhaps the most concerning performances among Liverpool's new arrivals have, however, come from Milos Kerkez. The former Bournemouth left-back has proven to be rash in some of his displays thus far, and it is clear that opposition managers are targeting the Hungarian, who has replaced Andy Robertson in Slot's first-choice line up.

At Turf Moor, Kerkez wasn't at the races. Burnley posed plenty of threat down their right-hand side during the first half, and Kerkez's frustrations perhaps boiled over when he tried to win a penalty with a blatant dive, only to earn himself a stupid yellow card. He was then a little fortunate to avoid picking up a second booking, and Slot was left with little choice but to replace the full-back after just 37 minutes.

With intense games against Atletico Madrid and Everton to come within the next week, Slot may opt to take Kerkez out of the firing line for the time being as he gets used to life on Merseyside.

Though Isak was nowhere to be seen following his deadline-day move, there were plenty of late-window signings who were able to make instant impacts for their new teams. Xavi Simons marked his Tottenham debut with an assist, Kevin produced a breath-taking cameo for Fulham following his club-record move from Shakhtar Donetsk and Gianluigi Donnarumma immediately showcased his shot-stopping ability for Manchester City.

However, the headline performance from a Premier League debutant came from the man tasked with replacing Isak at Newcastle: Nick Woltemade. Eyebrows were raised at the £69 million ($80m) that the Magpies paid to sign the Stuttgart striker, but he wasted no time in repaying that sum with an excellent all-round display against Wolves that he capped by nodding in the winning goal.

"It was a great moment for Nick," Eddie Howe said post-match. "I was very pleased with how he played today. You saw his qualities, his technical qualities that we've been discussing and his intelligence but most importantly for a striker, when the ball comes into the box, you need to be there and he was. It was a great finish. I'm really pleased for him personally because that just settles him down and relaxes him... I think it's a great start."

There was one late-window signing who would have liked to made a better first impression, however.

Alejandro Garnacho is the latest big-money forward to arrive at Chelsea in the Boehly-Clearlake era, and he won't be the last. If the Argentina international wants to stick at Stamford Bridge, though, then he is going to need to show better awareness than he did in stoppage time against Brentford on Saturday.

Despite having been given a warning earlier in the game, Garnacho fell asleep at the back post from a long throw, allowing Fabio Carvalho the freedom of the six-yard box to fire home an equaliser for Keith Andrews' side. Given the concerns around Garnacho at Manchester United were largely down to his application rather than his ability, that will be an early concern for Enzo Maresca as he and Garnacho prepare for trips to the Allianz Arena and Old Trafford over the next six days.

Back in Manchester, Garnacho's former club United slumped to a derby-day defeat at neighbours City as Erling Haaland produced one of the best all-round displays of his Premier League career thus far at the Etihad Stadium on Sunday.

Entering the game off the back of scoring five goals in Norway's thrashing of Moldova during the international break, Haaland looked full of confidence from the off, and almost opened the scoring inside the opening 20 seconds. Unlike some of his displays in a City shirt, he was keen to get involved whenever the home side tried to attack, while he routinely got his head on United set-pieces to ensure debutant goalkeeper Gigi Donnarumma was rarely troubled.

To cap off his day, Haaland produced two expert finishes in the second half to secure the 3-0 win, and he could have had a hat-trick had he not hit the post with the goal gaping. That brace took his Premier League goal tally for the season to five from his opening four games, and put him two clear of the chasing pack already in the race for the Golden Boot. Haaland missed out on topping the goal-scorers' list last term as Mohamed Salah ran away with the prize, but the Scandinavian looks hungry to regain the award he won in each of his first two campaigns in English football.

And finally, it's time for our weekly check-in on Graham Potter, who is back to being under intense pressure following West Ham's weak performance in losing 3-0 to London rivals Tottenham on Saturday. The Irons' win over Nottingham Forest looked to have got them on the right track following a woeful start, but their second-half capitulation against Spurs was another reminder of just how easy they have become to beat under Potter.

Tomas Soucek's red card at 1-0 obviously played its part in the loss, but West Ham's soft centre was routinely exposed by Tottenham, while the home side's inability to defend set-pieces puts them at a huge disadvantage given the renaissance dead-ball deliveries are enjoying in 2025-26. Part of that issue is due to the inability of goalkeeper Mads Hermansen to deal with crosses into the penalty area, and at £20 million ($27m), the ex-Leicester City man is already looking like one of the worst signings of the summer.

Things aren't going to get any easier for Potter, with games against unbeaten Crystal Palace, in-form Everton and title challengers Arsenal to come before the next international break in early October. The way things are going right now, it would be amazing if the West Ham boss were still in charge by then.