LONDON — Roberto Firmino ended Liverpool's 483-minute goal drought in the Premier League to set the champions on their way to a 3-1 win over Tottenham on Thursday and revive their faltering title defense.

Trent Alexander-Arnold and Sadio Mane also netted as Liverpool ended a five-game winless run in a league it dominated so resoundingly last season.

"We were really up for the game, everyone was at it," Alexander-Arnold said. "No one put too much of a foot wrong and it was an unbelievable performance from the lads."

The victory, which lifts Liverpool into fourth place, started with VAR ruling out an opener for Tottenham when Son Heung-min was adjudged to be offside.

Pierre-Emile Højbjerg reduced the deficit to 2-1 with a powerful strike shortly after Alexander-Arnold scored at the start of the second half, but the Liverpool right back set up Mane for the third that sealed the win.

While Liverpool moved within four points of leader Manchester City, Jose Mourinho's Tottenham is eight points adrift in sixth after its first defeat in 2021, albeit with a game in hand.

And Mourinho faces an anxious wait to discover the extent of Harry Kane's injury after the striker twice went down in the first half clutching his left ankle before being replaced at the interval.

"He is injured in both ankles," Mourinho said. "He said to compete with one pain he probably could, but both — it was very painful and very sore and he couldn't. He just couldn't.

"He is a guy with a good sacrifice spirit, he can fight against pain, but it was difficult for him."

There are problems at the back too for the north London club, which is in danger of failing to qualify for the Champions League for a second consecutive season after reaching the final in 2019 — losing to Liverpool.

Liverpool was forced to play midfielder Jordan Henderson at center back due to injuries and also lost Joel Matip at halftime with ankle ligament damage.

But it was Tottenham's back three looking more fragile,

"We were punished by our individual mistakes," Mourinho said. "It's nothing new for us."

How different, though, this game might have gone had Son not been marginally offside when he was released by Kane before scoring.

Liverpool was more threatening going forward after that, with Mane testing Hugo Lloris with tame shots before setting up the opener in the fourth minute of stoppage time at the end of the first half. Firmino tapped in after Mane passed across the face of goal, scoring Liverpool's first league goal since Dec. 27.

It was clear from Mourinho's post-match comments that it was a tense atmosphere in the dressing room at halftime.

"It is the mood of a team that is difficult to accept that you are losing," Mourinho said. "It's a mood where people are not happy. But then we have to move on."

But Liverpool doubled its lead two minutes into the second half when Lloris spilled Mane's shot into the path of Alexander-Arnold.

Tottenham threatened an immediate comeback when Højbjerg powered in a shot from outside the area.

There was another break for Tottenham when Mohamed Salah's goal was ruled out because Firmino was adjudged to have handled in the buildup despite Eric Dier grappling the Brazilian.

But Liverpool restored its two-goal cushion in the 65th when Alexander-Arnold's long cross came off Joe Rodon and fell for Mane to strike into the roof of the net.