Diogo Jota came off the bench to score a late winner as Liverpool rallied from a goal down to beat West Ham 2-1 at Anfield.
The Portuguese linked up brilliantly with fellow substitute Xherdan Shaqiri five minutes from time to ensure the champions denied their in-form opponents a share of the points.
Liverpool were forced to come from behind after Pablo Fornals' well-taken early goal, which was cancelled out by Mohamed Salah's penalty moments before the break.
The turnaround helped Jurgen Klopp's men prevail as they extended their unbeaten league run at Anfield to 63 games, equalling a club record streak set between February 1978 and December 1980.
As they would have expected, Liverpool started the game by taking complete control of possession, probing a penned-in West Ham defence.
But after holding firm throughout their early examination, the visitors showed that they only needed one chance to get on the scoresheet, Fornals latching onto a poor Joe Gomez clearance and steering the ball in off a post.
Indeed, the Hammers were the best side for large parts of the first half, finding their way deep into opposition territory with worrying regularity from the hosts' perspective.
Still, they could not entirely manage the Liverpool threat and, with a half-time lead seemingly in the bag, conspired to give away a penalty as Arthur Masuaku clumsily clipped Salah, who converted from the spot.
Despite that setback, the Hammers' first-half performance meant they had every reason to come out for the second period brimming with confidence, and they wasted little time in underlining their ambition after the restart as Masuaku's cross was almost poked home by Fornals.
With Liverpool still struggling to find their cutting edge by the 70th minute, Klopp looked to the bench, introducing Shaqiri and Jota.
And the Reds manager thought that move had paid off handsomely when the latter turned the ball home after Sadio Mane had been denied from close range.
However, a VAR check showed the Senegalese to have fouled goalkeeper Lukasz Fabianski in following the ball in, prompting referee Kevin Friend to chalk the goal off after checking replays.
Jota would simply have to wait a little longer for his big moment, though, with an inch-perfect Shaqiri ball setting him up to thrash the ball home at the Kop end with five minutes remaining.
What does it mean? Reds grind it out again
Despite not being at their convincing best once again, Liverpool leapfrogged Merseyside rivals Everton to take top spot in the Premier League.
Klopp will want more in terms of performance from his players as the season progresses but, in terms of results, will have few complaints about their start to the campaign.
Phillips shines on league debut
A surprise pick to partner Gomez at the heart of the home defence, Nathaniel Phillips showed Klopp was right to put faith in him as he kept Sebastien Haller quiet.
The Englishman comfortably surpassed his team-mates in making nine clearances, none more important than the powerful last-minute header that kept a West Ham corner at bay.
Firmino struggles again
Another Liverpool win, another difficult day for Roberto Firmino, whose poor form is even more concerning from his point of view given the pressure Jota is exerting on his position in the team.
The Brazilian's 70 minutes on the pitch resulted in just 43 touches, 34 passes, and zero shots or key passes.
Key Opta facts
- Only Aston Villa in 1897-98 (17) have conceded more goals in their first seven league matches as reigning champions than Liverpool (15). The Reds took 23 games to concede 15 goals last season.
- Since David Moyes' first game back in charge, West Ham have dropped more points from winning positions than any other side in the Premier League (16).
- Liverpool have conceded the first goal in three of their four home league games this season - as many times as they did in all 19 league matches at Anfield last term.
- The Reds have scored each of the last 18 penalties they have taken in all competitions (excluding shoot-outs), with Mohamed Salah himself netting his last 13 for the club.
- Diogo Jota is just the second player to score in all of his first three Premier League appearances for Liverpool at Anfield, after Luis Garcia in October 2004.
Liverpool turn their attentions to the Champions League in midweek as they travel to Atalanta, followed by a huge clash with Manchester City. West Ham, meanwhile, have a week off before a London derby against Fulham.