Arsenal began the New Year by inflicting their first significant blow of the season on a title rival, but only after surviving a late fightback to beat Chelsea 3-2 at Highbury.
Having drawn against Chelsea and Liverpool, as well as losing at Manchester United, Arsene Wenger's side finally managed to damage the title challenge of Claudio Ranieri's team.
Marcel Desailly's own goal was all that separated the sides until Giovanni van Bronckhorst and Thierry Henry looked to have made sure of victory in the final 10 minutes.
However, Mario Stanic and Emmanuel Petit struck within the space of just over two minutes to ensure Arsenal a nervous finale before they confirmed an eight-point advantage over their London rivals.
Arsenal would have been in an even more dominant position without Paul Scholes' late winner for Manchester United at Old Trafford.
But there was still considerable relief at the final whistle after Chelsea's desperate late surge for an equaliser.
Amid pouring rain, the visitors, with another six alterations to their ever-changing line-up, immediately announced their intention to take the game to the Premiership leaders.
Enrique de Lucas burst into the penalty area but he mis-hit his shot wide and, with just nine minutes gone, all of the visitors' early pressure had counted for nothing when they went behind.
The goal was a classic Arsenal counter-attack, with Robert Pires firing a crossfield ball into the path of the surging figure of Ashley Cole.
His cross found Dennis Bergkamp and while the Dutchman failed to make clean contact with the ball, it bounced, via an apparent deflection off Desailly, into the ground and over Carlo Cudicini into the net.
That was the cue for Arsenal to start imposing themselves in midfield, although it was still a largely scrappy affair in which the Gunners' main threat continued to come on the break.
Graeme Le Saux did test out David Seaman with a firm drive which the Arsenal keeper did well enough to parry but even better to recover and dive on the rebound ahead of Hasselbaink.
Otherwise, however, Chelsea started to lose their way, with Sylvain Wiltord and Patrick Vieira both threatening to extend Arsenal's advantage.
And although the visitors again started positively after the restart, with Seaman gathering a snap-shot from de Lucas, Arsenal almost responded in exactly the same way as the first-half.
Henry's pace and power took him clear of William Gallas but his cutback went just inches behind Gilberto as the Brazilian raced into the penalty area unmarked.
The Frenchman continued to pose the greatest menace, with his incredible pace taking him past first Gallas and then Desailly as he twice threatened Cudicini's goal.
Arsenal's lead nevertheless continued to be slender and both managers looked to seize a tactical advantage as the game wore on.
On came Jesper Gronkjaer for Chelsea to give more penetration. Wenger countered with van Bronckhorst down the same flank and then replaced Wiltord with Lauren on the other wing.
Ranieri's response was to bring on Eidur Gudjohnsen up front, with Gianfranco Zola moving deeper, before the Italian hobbled off, to be replaced by Stanic.
Wenger, meanwhile, made his own final move, with Kolo Toure on for Bergkamp, and Henry therefore left as his team's only real attacking outlet.
That, however, was reckoning without van Bronckhorst's superb 20-yard finish to cap a move which he started with a crunching tackle on the halfway line before Henry provided the vital link.
Just a minute later, Henry looked to have made sure of victory as he cut inside Gallas and delivered a shot which Cudicini should have saved only to see the ball bobble through his grasp and into the net.
However, Chelsea were, even then, amazingly still not out of it.
First, Stanic headed home from point-blank range after Hasselbaink had nodded a corner back across the six-yard area with four minutes left.
And then Seaman collided with Sol Campbell to provide Petit with an open goal against his former club to spark a frantic finale before the Gunners eventually prevailed.
Arsene Wenger insisted his Arsenal team are back on track as he hailed the
winning mentality that overcame their tiredness to inflict a significant blow on
title rivals Chelsea.
Wenger admitted he could have hardly dared to imagine that Arsenal would start
the new year five points ahead of Manchester United and with their lead over
Chelsea extended to eight points.
After all, although Arsenal are not yet back at their peak, they have taken 10
points out of a possible 12 from their games over the festive period following
their 3-2 win against the Blues.
Wenger declared: 'It was a tough game but we have shown a fantastic spirit
'We needed to dig deep again to win the game but, once again, this team found
the resources, even if you could see that we were jaded physically after two big
games in four days on a muddy pitch.
'We won the game mentally as we really wanted to do it. I like to win games
like that when you're tired as it's a great sign of the spirit of the players.
'These are not just great players but they are winners. They are back focused
on the championship. They really want it and are really committed to it.
'One of the most important things in a season is to beat your main rivals at
home. We didn't beat Liverpool but we kept them nine points behind and it was
more important to beat Chelsea.
'I'm very confident. We know we can win the title but we want to find
consistency back. In my opinion, the team is back on track, focused and ready
for consistency again.'
United, who scraped a late winner against Sunderland, look to be Arsenal's
main challengers, although Wenger insisted: 'Manchester United are back there
but it's too far away to say it's only a two-horse race.'
The Arsenal boss maintained that Dennis Bergkamp should be credited with the
opening goal, even though the club had officially given it as an own goal to
'Of course, it was deflected but his intention is to put it in and when you
score a deflected goal, it's the guy who takes the shot who gets the goal,'
Arsenal later extended their lead to 3-0 through goals by Giovanni van
Bronckhorst and Thierry Henry, whom Wenger described as 'outstanding'.
Chelsea fought back late on through substitute Mario Stanic and Emmanuel
Petit, even if Wenger believes that David Seaman was fouled in the build-up to
that final goal.
'David told me that Jimmy Floyd Hasselbaink put his foot in on his hand and
that's why he dropped the ball. The way that he explained it to me, it looks
like it was a foul,' he said.
Arsenal nevertheless held on, leaving Chelsea boss Claudio Ranieri praising
the home side, and Henry especially, while lamenting his side's fortunes over
the festive period, with one point out of a possible nine.
'If we'd had a little luck, we could have drawn the match but the players
showed great pride and fought a lot for every ball,' he added.
'We have never spoken about the title. Of course, everybody wants to win it,
but it's important for us to continue with good football, although not
necessarily in this way, maybe a luckier way.'
Ranieri does not believe that a knock sustained by Gianfranco Zola is too
serious, although he will check the striker's fitness again tomorrow ahead of
this weekend's FA Cup tie against Middlesbrough.