Chelsea scored against the run of play on 24 minutes when David Luiz's free kick caught out Liverpool, with goalkeeper Simon Mignolet not set as the ball whistled in off the post.

Liverpool hit back in the second half when James Milner headed back across goal for Georginio Wijnaldum to nod past goalkeeper Thibaut Courtois.

Chelsea had the chance to make it 2-1 when Costa went down in the box under Joel Matip's challenge, but the striker was denied by a low Mignolet save.

Arsenal's title hopes took a significant dent as they suffered a 2-1 loss to Watford at Emirates Stadium.

Watford took a surprise lead in the 10th minute when Younes Kaboul's free kick deflected off Aaron Ramsey to leave goalkeeper Petr Cech wrong-footed.

And it was 2-0 just three minutes later when Troy Deeney pounced after Etienne Capoue's initial shot was saved by Cech.

The Gunners pulled a goal back through Alexi Iwobi, who guided home at the back post from Alexis Sanchez's chip.

But Arsene Wenger, who was watching from the stands due to suspension, saw his side fail to claw a way back into the match.

Sunderland climbed off the foot of the table with a goalless draw against Tottenham Hotspur at the Stadium of Light.

The point also sees Spurs climb above Arsenal into second on goal difference.

Premier League champions Leicester City suffered their 12th loss of the season as Burnley's fine home form continued with a 1-0 win at Turf Moor.

Sam Vokes scored the only goal of the game with three minutes left on the clock, reacting quickest to poke home in the box.

Swansea City made it back-to-back wins under manager Paul Clement as they beat Southampton 2-1 at the Liberty Stadium.

Alfie Mawson broke the deadlock for Swansea in the first half, heading home from Gylfi Sigurdsson's corner.

Southampton levelled in the 57th minute thanks to Shane Long's close-range finish from Ryan Bertrand's delivery.

But Swansea restored their lead with 20 minutes left on the clock as Sigurdsson slotted home with his left foot.

Sam Allardyce secured his first Premier League win as Crystal Palace manager as his side triumphed 2-0 at Bournemouth.

Palace broke the deadlock two minutes into the second half when Scott Dann diverted home following Damien Delaney's flick.

And the success was sealed when Andros Townsend sent in a cross for Christian Benteke, who nodded in.

Struggling Middlesbrough fought back for a point in their clash with West Bromwich Albion at the Riverside.

The visitors went in front on six minutes when James Morrison shot low beyond goalkeeper Victor Valdes.

Boro hit back in the 17th minute when Alvaro Negredo dusted himself down after being felled in the box to slot home his penalty.