Dec 13 (Reuters) - Ashley Williams powered home a towering header in the 86th minute as Everton fought back to claim a 2-1 win over Arsenal as the title hopefuls blew the chance to return to the Premier League summit on Tuesday.
It was the first league defeat for Arsene Wenger's men since they lost to Liverpool on the opening day of the season and their first on the road since March.
More importantly, it handed Chelsea the chance to go six points clear at the top when they visit bottom club Sunderland on Wednesday.
It looked like business as usual for the visitors, who have been scoring freely in recent weeks, when Alexis Sanchez netted his 12th league goal of the season with a deflected free kick after 20 minutes.
Everton though warmed to the task, levelling through Seamus Coleman's header a minute before halftime.
With the seconds ticking away towards the end, Williams rose high to nod Ross Barkley's corner into the net for his first Everton goal, securing the team's first win since the end of October.
It moved Everton up to seventh in the table and offered some cheer to manager Ronald Koeman.
"We showed unbelievable spirit to come back and we deserved the win," the Dutchman told BT Sport.
Everton struggled for confidence in the early stages as they retreated, inviting Arsenal to attack.
Francis Coquelin was brought down on the edge of the area and Sanchez stepped up to hit a tame free kick that looked to be covered by Maarten Stekelenburg until it deflected off Williams and beat the keeper's outstretched hand.
The goal put Sanchez joint top of the league's scoring charts with Chelsea's Diego Costa.
It also seemed to spark life into the hosts who gradually came out of their shells with Aaron Lennon slicing an effort wide before Coleman levelled with a glancing header from Leighton Baines' cross.
Mesut Ozil blasted a good chance over for Arsenal at the start of the second half but Everton were on top and pushing for the winner when Williams sent Goodison Park wild.
In a frenetic finale, Everton defender Phil Jagielka was sent off for a second booking in the fourth minute of stoppage time.
Arsenal also had two efforts cleared off the line and somehow prevented the home team grabbing a third goal when keeper Petr Cech was caught upfield.
Reporting by Toby Davis; Editing by Tony Jimenez