Liverpool crashed to a third successive defeat as Estevao Willian's last-gasp strike condemned the Premier League champions to a 2-1 defeat against Chelsea on Saturday.
Arne Slot's side were rocked by Estevao's close-range finish in the final seconds at Stamford Bridge after Cody Gakpo's second-half equaliser had cancelled out Moises Caicedo's fine opener for the Blues.
After making a perfect start to the season with seven wins in all competitions, including five in the Premier League, Liverpool have suffered an unexpected blip with shock defeats at Crystal Palace, Galatasaray and Chelsea.
Having lost to Palace in the closing moments last weekend, this was another agonising blow for Liverpool, who had made a habit of scoring late winners themselves in the early weeks of the season.
Those late goals had papered over the cracks as Liverpool struggle to gel following Slot's close-season spending spree.
Injury-hit Chelsea were well worthy of a dramatic win at Stamford Bridge to end their three-game winless run in the Premier League.
One-time Liverpool target Caicedo blasted the Blues into a half-time lead with a blistering strike into the top corner on 14 minutes.
Alexander Isak's £125 million move to Liverpool last month broke Caicedo's record as the most expensive Premier League player of all-time.
The Swedish striker is still yet to score a league goal but his deft touch teed up Gakpo to equalise just after the hour mark.
However, Chelsea were not to be denied as Estevao slid in at the far post to meet Marc Cucurella's cross deep into stoppage time, sparking wild celebrations from manager Enzo Maresca who was shown a red card for sprinting down the touchline.
Liverpool now trail Arsenal by one point, while Chelsea edge up to sixth.
Cucurella was full of praise for team-mate Estevao.
"He came into the game maybe his first time against Liverpool in the Premier League and the pace of the game was very high. He came with the personality. Hato as well, he came in the middle of the game," he told Sky Sports.
"It is difficult to come from the bench into these games with a lot of intensity and transition. These two players deserve this moment. It is never easy to adapt to the Premier League, today I think they show their quality."
Earlier in the day, Mohammed Kudus scored his first Tottenham goal to keep Thomas Frank's team riding high.
Kudus' second-half strike from the edge of the box secured a 2-1 win at Leeds.
Spurs were unbeaten in their last seven games in all competitions and have lost just once in the league under Frank, who took charge in the summer.
Kudus was one of Frank's big signings in the offseason — joining from West Ham — and the forward produced the decisive moment at Elland Road where he cut in from the right and fired low past Karl Darlow in the 57th minute.
Spurs led through Mathys Tel, whose deflected shot rocketed into the top corner.
Leeds, who were unbeaten at home since February, equalised through Noah Okafor from close range in the 34th.
