Carlos Tevez returned from exile to keep Manchester City's title challenge on course as the Argentine substitute played a crucial role in a 2-1 win over Chelsea at Eastlands.
Inspired by Tevez, City scored twice in the final 12 minutes to move to within one point of Premier League leaders Manchester United, having played the same amount of games as their bitter rivals.
Elsewhere, Arsenal leapfrogged Tottenham into third place as Arsene Wenger's side won 1-0 at Everton, while their north London rivals were held to a 1-1 draw by Stoke.
Queens Park Rangers staged a sensational fightback to boost their survival hopes with three late goals in a 3-2 win against Liverpool.
At Eastlands, Tevez, who had fallen out with City boss Roberto Mancini over his refusal to warm-up during a Champions League tie at Bayern Munich in September, made his first appearance for nearly six months as a 66th minute replacement for Nigel de Jong.
Mancini sent the striker on with City trailing 1-0 to Gary Cahill's deflected 60th minute goal and it proved an inspired move as the hosts levelled in the 78th minute.
Tevez's compatriot Sergio Aguero stroked home a penalty after Michael Essien was penalised for handball.
It was Tevez who played the key role in Samir Nasri's 85th-minute winner as the former Manchester United player slipped a perfectly-weighted pass through for the French midfielder to fire the winner that set a Premier League record for City's 20th successive home win.
That was Chelsea's first defeat under interim boss Roberto Di Matteo and it left the Blues five points behind Tottenham in the race for fourth place.
"I'm happy, because he (Tevez) did well," Mancini told said later. "Also he's not in good form, I don't think he's fit 100 per cent, but that's football.
"Carlos is maybe not 100 per cent but he knows football and he was important because he was incredible for us.
"I have spoken with Carlos every day this month and he knows he had to come off the bench and play 20 minutes in this game but he can play more in the future.
"I don't think we deserved to go behind, but we had the desire to win this game. It's more than three points this game. After their goal I felt squeaky bum time!"
The feel-good factor extended beyond the manager's dug-out with Tevez's team-mates clearly content to have him back in the fold. "I'm really happy for him," added Nasri of Tevez.
"He's showed great spirit since he's been back and showed in this match he can be really important until the end of the season. It's good that it's him that gave me this assist.
Meanwhile, Arsenal took full advantage of Tottenham's latest slip to move one point clear of Harry Redknapp's side.
Thomas Vermaelen got the only goal at Goodison Park in the eighth minute as he rose highest to head in Robin van Persie's corner.
There was controversy about the win however as Everton appeared to have equalised through Royston Drenthe, only for the Dutch midfielder's effort to be harshly ruled out for offside.
"I felt the attitude was always very good for the players and confidence comes from results. We've turned a few results around and that creates belief," Arsenal boss Arsene Wenger said. "I believe we have learned from a difficult period."
At Loftus Road, QPR climbed out of the relegation zone in dramatic fashion with a sensational win over Liverpool.
Mark Hughes's side appeared destined for another dispiriting defeat when Sebastian Coates opened the scoring with a stunning 54th minute scissor-kick and Dirk Kuyt then increased Liverpool's lead in the 72nd minute.
But Shaun Derry gave QPR a glimmer of hope with a 77th minute header and former Liverpool striker Djibril Cisse nodded in the 86th minute equaliser.
That set the stage for a dramatic finish as Jamie Mackie completed the comeback with a cool stoppage-time winner.
"We've come back from a situation where we looked dead and buried," Hughes said. "We had nothing to lose and thought let's go for it."
It was a significant blow for Spurs, who needed a stoppage time equaliser from Rafael van der Vaart to rescue a draw against Stoke.
Spurs struggled to find any momentum once the action started and fell behind in the 75th minute when Cameron Jerome poked home Robert Huth's header.
Van der Vaart's last-gasp headed equaliser at least stopped Spurs suffering a fourth successive defeat, but it was only a slender consolation.
"It was a game I thought we would win and we're disappointed to only take a point but it might come in handy at the end of the season," Redknapp said.
