Arsenal cast aside their Premier League away day blues to wreck Paul Clement's Liberty Stadium debut as Swansea boss.
The Gunners had managed only one away league win since the end of October, but a comfortable 4-0 victory put them back in the top three on goal difference.
Goals from Olivier Giroud and Alexis Sanchez, sandwiched between two deflected Alex Iwobi efforts credited as own goals to Jack Cork and Kyle Naughton, put them in cruise control and sent Swansea to the bottom of the table.
Clement, Swansea's third manager in a troubled season, had promised an end to the defensive disarray that had marked the end of his predecessor Bob Bradley's short reign.
For much of the first half Swansea were as good as Clement's word as they fought tenaciously and stopped Arsenal having a meaningful sight of their goal.
But once Giroud, scoring for the fifth successive game, had opened the floodgates after 37 minutes, Swansea's failings were all too evident in a one-sided second half.
What had appeared to be a difficult afternoon for Arsenal turned into a comfortable one as Iwobi efforts went in off Cork and then Naughton, before Sanchez volleyed home his 14th league goal of the season from close range.
Clement's desire for a fast start was realised as Swansea began on the front foot and Petr Cech had to push Naughton's shot around the post.
Cork and Gylfi Sigurdsson also fired over as Arsenal struggled to hit their stride despite dominating both possession and territory.
The visitors' attacks mostly headed down cul-de-sacs and their sense of frustration was reflected by Sanchez -- as he had done at Bournemouth in the Gunners' last league game -- showing dissent to a teammate after a misplaced pass.
Within seconds, however, Sanchez was switched on to test Lukasz Fabianski with a stinging 20-yard drive.
Arsenal were hinting at better things and the breakthrough arrived after Giroud had failed to connect with an Aaron Ramsey cross which flashed across the Swansea goal.
Sanchez retrieved the ball on the left and centred for Mesut Ozil, whose header hit Alfie Mawson to present Giroud with the simplest of tasks to convert his 10th goal of the season.
Swansea felt they had a lifeline seconds before the interval when Ki Sung-Yueng burst into the penalty area and went down under Laurent Koscielny's challenge.
It appeared there had been some contact, but referee Mike Jones felt Ki had initiated it by trailing his leg into Koscielny and booked the South Korean for diving.
Arsenal did not look back after that, despite Ramsey failing to make the most of a shrewd Sanchez pass when he fired at the legs of Fabianski.
Iwobi benefited from fortunate deflections after 54 and 67 minutes to put the contest to bed before Sanchez capped his second-half excellence with a predatory finish 17 minutes from time.
It was the fourth time in the last nine league games that Swansea have conceded at least four goals and Clement has a tough job to save them from relegation.