Arsenal climbed above Manchester United to the top of the Premier League on Saturday thanks to Samir Nasri's spectacular double in a 2-1 win over Fulham.
With United's match at Blackpool postponed because of a frozen pitch, previous leader Chelsea and Arsenal - who were both two points adrift in joint second - knew wins could send them provisionally into first place.
Chelsea wasted its chance by only drawing 1-1 at home to Everton, the Blues' fourth match without a victory, and Arsenal took advantage at Emirates Stadium.
Nasri opened the scoring in the 14th minute and the in-form France midfielder then grabbed the winner with 15 minutes remaining for his 11th goal of the season in all competitions.
"It was a combination of touch, intelligence, special talent and calmness as well," Arsenal manager Arsene Wenger said of Nasri's two finishes.
Arsenal is one point above United, which is a point clear of stuttering Chelsea. The defending champions have only won once in the league since the end of October and were booed off by their fans after Jermaine Beckford equalized in the 86th for Everton.
Carlos Tevez scored the winner as Manchester City beat Bolton 1-0 to stay fourth, and three points off the pace. Fifth-place Tottenham drew 1-1 at Birmingham and is three points behind City.
Nasri has been given added responsibility this season with fellow playmaker Cesc Fabregas struggling with fitness problems but the France international is responding with his best run of form for the London club.
"Many people questioned me when I took him here but he is showing that he is an exceptional talent and I think there is more to come from him," Wenger said.
Nasri had a cutting edge against Fulham that his teammates lacked, putting the hosts ahead by running onto Andrey Arshavin's pass, dummying past two defenders and rifling a shot into the roof of the net.
Senegal striker Diomansy Kamara equalized for Fulham in the 30th, taking advantage of a clash of heads between Arsenal center backs Sebastien Squillaci and Laurent Koscielny that forced the latter out of the game with a concussion, but Nasri's eighth of the campaign won it for the Gunners.
Substitute Robin van Persie squared the ball to Nasri, who showed sublime skills to go round goalkeeper Mark Schwarzer, spin and shoot home from a tight angle.
The win left Wenger again answering questions about whether Arsenal finally has the maturity to win the title.
"We are good enough to go on, that is for sure," he said. "We have the spirit, we have the quality but we face tough opponents. And it will be down, as I have said already many times here, to consistency."
Chelsea welcomed back captain John Terry and midfielder Michael Essien but still looked vulnerable. The Blues have taken just five points from a possible 18 in their last six matches and could easily have lost to Everton, which dominated the final stages.
Didier Drogba gave Chelsea the lead with a penalty in the 42nd minute, the striker's seventh goal of the season, after Nicolas Anelka had been sent tumbling by visiting goalkeeper Tim Howard.
After Jack Rodwell hit the post for Everton, Beckford secured a point with his 86th-minute header and Chelsea walked off the pitch to boos from the home crowd.
"I am disappointed and angry," Chelsea manager Carlo Ancelotti said. "Not just because of the result. We played good football in the first half and the second half was totally different. We played the long ball. We were a little bit scared. I didn't like this.
"I am worried yes, because we haven't won a lot of games. The second half was totally wrong."
The top four are separated by just three points thanks to 10-man City's narrow win over local rival Bolton, courtesy of Tevez's 10th goal of the season.
The Argentina striker was set free by Yaya Toure through the middle and drilled a shot into the corner for City's first at home goal since October.
City wasted a number of chances to increase the lead and then had left back Aleksandar Kolarov sent off in the 79th after picking up his second yellow card.
Mario Balotelli and David Silva both hit the framework for City in the second half, while Bolton nearly equalized in the 71st following an error by goalkeeper Joe Hart, but Vincent Kompany cleared off the line.
City manager Roberto Mancini said his strikers need to improve their finishing if the team is to stay in title contention.
"We are too selfish (in front of goal)," Mancini said. "We had maybe 15 chances to score. When you have a lot of chances you think the game is easy. You shoot when it is better to pass the ball. We must improve this situation."
Spurs lost ground as Craig Gardner's 81st-minute goal denied them all three points at St. Andrew's.
The midfielder ran onto Nikola Zigic's downward header and nodded home from eight yards to deny Spurs a fourth straight league win.
The visitors had gone ahead in the 19th minute when Cameroon defender Sebastien Bassong scored from close range after Birmingham goalkeeper Ben Foster flapped at a free kick.
Blackburn bounced back from its 7-1 defeat to Manchester United last weekend by beating Wolverhampton 3-0 thanks to goals by David Dunn, Brett Emerton and Ryan Nelsen. Wolves went bottom because of the loss.
In the day's other game, Wigan twice came from behind to draw with Stoke 2-2.
Danny Collins' own goal canceled out Robert Huth's opener and although Matthew Etherington restored Stoke's lead, Tom Cleverley's deflected shot gave third-bottom Wigan a point.
