Arsenal dealt Chelsea's title hopes a blow by holding the champions to a pulsating 1-1 draw on Sunday that boosted the chances of Premier League leaders Manchester United.
Arsenal's French midfielder Mathieu Flamini looked to have rifled in a 78th minute matchwinner, only for Chelsea's Ghanaian midfielder Michael Essien to smash home a stunning 30-metre piledriver in the 86th minute at Stamford Bridge.
The real winners on the day were United, who beat Manchester City 3-1 on Saturday and are now eight points ahead of second-placed Chelsea after playing a game more.
United lead with 44 points from 17 games, Chelsea have 36 from 16, followed by Portsmouth and Liverpool on 28. Arsenal moved up to sixth on 26 points from 16 games.
Though the result was a setback for Jose Mourinho's side, they came desperately close to suffering a first home league defeat since February 2004, when they lost to Arsenal.
However, they could also have snatched victory in injury time when Essien and Frank Lampard both hit the woodwork.
"We were losing at home with five minutes to go and had an incredible reaction and should have won it," Chelsea manager Jose Mourinho told Sky Sports.
Arsenal, who had lost their last three away league games, packed their midfield in an effort to combat the physical presence of the champions.
Chelsea left back Ashley Cole, facing his old club for the first time since an acrimonious August transfer, was booed by Arsenal fans and cheered loudly by the home crowd every time he touched the ball.
Arsenal, though entertaining going forward, had let-offs when Frank Lampard struck a post and Essien had an effort cleared off the line by Cesc Fabregas.
Arsenal keeper Jens Lehmann and Didier Drogba were booked after an almost comical shoving match, while Chelsea coach Jose Mourinho tried to add more bite by sending on wingers Arjen Robben and Shaun Wright-Phillips for Geremi and Shevchenko.
Robben and Lampard nearly made Arsenal's Swiss defender Philippe Senderos pay for a wayward crossfield pass, forcing Lehmann into a series of desperate blocks.
But Arsenal struck against the run of play, after a patient build-up, Alexandr Hleb squared for Flamini, whose shot from the edge of the box which Hilario got a hand to but could not stop.
The lead lasted only eight minutes though. Lampard laid the ball off in midfield for Essien and instead of hoisting the ball into the area, he smashed it first time into the top left corner past a helpless Lehmann.
Injury time produced more drama as Essien, from point-blank range, struck the underside of the bar and Lampard hit the post after Lehmann spilled the ball into his path.
Mourinho accepted that Arsenal were the better side in the first half but said he was surprised by their negative approach.
"Everyone saw who tried to win the game," he said. "I accept the draw but it was a bit of a surprise that a team 15 points behind the leader came here not to win, to go for the draw, it's almost saying we don't want to win the Premiership.
"We had a lot of chances, even in the first half when we didn't play well. We had big chances before they scored, we then showed a good emotional reaction, got an unbelievable goal, and then had great chances in the last minute."
Asked how United manager Alex Ferguson would have greeted the result he said: "I think he must be happy now, he can say we've dropped two points but if he thinks it's over he is in trouble."
Arsenal manager Arsene Wenger defended his tactics. "We came here with a very young team and played some good football," he said.
"We had a very young defence and I wanted to give them a bit of protection today against a team who have a lot of physical strength through the middle.
"We tried to win the game and nearly did that. I knew the final part of the game would be difficult for us physically but when you get so close to winning of course you want to keep it going."