Arsenal stormed back to the top of the Premier League with a fine return to form against beleaguered London rivals Chelsea.
Having not won any of their past four games, the Gunners eased to a 3-1 victory to leapfrog Manchester City for at least the next 24 hours.
Captain Martin Odegaard hit a brace as Gabriel Jesus wrapped up the points before the interval, with Chelsea slipping to a sixth successive defeat under interim boss Frank Lampard.
Recalled Noni Madueke at least hit a rare consolation goal for the Blues, who have now lost six of their past seven meetings with Arsenal.
While it was a night to remember for skipper Odegaard, it was one his predecessor will want to forgot in a hurry, Pierre-Emerick Aubameyang starting for Chelsea for the first time since facing Arsenal on November 6 but lasting just 45 minutes before being substituted.
Arsenal boss Mikel Arteta had refused to rule his side out of the title race despite a four-game winless run which culminated in a galling defeat to rivals City last week.
This result takes them back to the summit, two points clear of City but having played two games more and with Pep Guardiola’s men in fine form ahead of their visit of West Ham on Wednesday.
It was a lively start for the hosts, with Bukayo Saka next to test Kepa, the England forward’s header palmed away by the Chelsea goalkeeper.
There was nothing the stopper could do shortly afterwards, however, only getting a glove to a fine Odegaard finish from a Xhaka cross with both players afforded the time and space to put Arsenal into a deserved lead.
Chelsea almost hit back through Ben Chilwell but his England colleague Aaron Ramsdale pushed his shot behind at full stretch.
Lampard reacted to an abject first half by replacing the ineffectual Aubameyang, who had just nine touches on his Emirates return – four of which were kick-offs.
Xhaka nearly went from provider to scorer but Kepa pushed his strike away before Jesus could not keep an effort down with Arsenal rampant.
Chelsea would pull a goal back, just their second in eight games, as Madueke bundled home his first Premier League goal after skipping inside Oleksandr Zinchenko.
However, unlike in recent weeks when Arteta’s defence has creaked under pressure, they stood firm to see out the game and secure a vital win.