Alexis Sanchez's 14th goal of the season added the finishing touch to Arsenal's convincing 4-0 Premier League victory over relegation battlers Swansea on Saturday elevating them to third.

The in-form France striker Olivier Giroud gave the visitors a first half lead before own goals from Jack Cork and Kyle Naughton and an opportunist strike from Chilean star Sanchez completed the job.

The Gunners rose to third from fifth and head Liverpool on goal difference although they can go above Arsenal again if they draw or beat Manchester United on Sunday.

The crushing defeat and Hull's win over Bournemouth sees Swansea fall to the bottom of the table a point from safety.

It was a chastening home bow for Swansea manager Paul Clement. The Englishman -- lured from being Carlo Ancelotti's assistant at Bayern Munich to replace Bob Bradley -- saw his side capitulate in a second half that was totally one-sided.

They put up more of a fight in the first-half and could have gone in front in the 10th minute when Petr Cech was called upon to push aside a firm strike from Naughton.

Three minutes later, Gylfi Sigurdsson was inches over with a shot from 20 yards after Wayne Routledge had opened up the Arsenal defence.

It took Arsenal 27 minutes to muster any kind of chance. Even then, it was a shot from distance from Sanchez that Lukasz Fabianski saved comfortably at the foot of his near post.

Swansea, who responded well to the continual prompting of Clement from the touchline, got numbers around the ball and made life increasingly difficult for the visitors.

But then, just as Arsenal appeared to be heading towards an interval dressing down, they struck through Giroud, in the 37th minute.

The most sublime of moves involving Mesut Ozil, Giroud and Aaron Ramsey created the platform and when Ozil was denied with a tame header, from a Sanchez cross, Giroud pounced to convert from four yards.

Two minutes before the break, Swansea thought they had earned themselves a penalty when Ki Sung-yueng appeared to be tripped by Laurent Koscielny after Fernando Llorente's delightful touch had opened up the Arsenal defence.

Referee Mike Jones marched up to Ki, booked the South Korean for what he felt was a dive and duly awarded Arsenal a free kick.

Arsenal began the second half at a decent pace and both Sanchez and Alex Iwobi had opportunities to score before Ramsey was denied by a desperate save, with his feet, by Fabianski.

The goal did come, however, when Iwobi's shot looped off Cork and into the back of Fabianski's net.

Without any genuine threat at the opposite end, Swansea were never likely to find a way back into the game.

Routledge did have a shot saved by Cech, on the hour, but there was precious little else over which to enthuse as Arsenal strolled to victory.

A third followed 13 minutes later -- Naughton turning in Iwobi's cross -- and soon afterwards it was four.

Alex Oxlade-Chamberlain nipped in behind, in the 74th minute, and though Routledge got his foot on the winger's cross, the ball popped up to Sanchez who scored from eight yards.