Swansea scored two own goals as Arsenal gave Paul Clement a home debut to forget in a 4-0 thrashing at the Liberty Stadium on Saturday.
Swansea had a chance to move out of the bottom three for the first time since October 15 with a win but their task was made tougher when Olivier Giroud opened the scoring just before half-time - his fifth goal in five games.
Jack Cork and Kyle Naughton then put through their own net after the break - both from Alex Iwobi crosses - before Alexis Sanchez also got in on the act with his 14th goal of the season.
However, all didn’t look well with Sanchez when he was substituted, the Chilean cutting a frustrated figure on the bench with his overcoat pulled over his head.
Arsenal have now taken 29 points from a possible 33 against teams in the bottom half this season and their next three home games are against Burnley, Watford and Hull.
They move to within five points of league-leaders Chelsea, who play Leicester City on Saturday evening.
Mesut Ozil returned to the Arsenal team in one of two changes made by Arsene Wenger from the 3-3 draw with Bournemouth in the Premier League.
The Gunners are the only Premier League team yet to concede in the opening 15 minutes this season, but Swansea gave it a good go forcing Petr Cech into a flying save as Naughton took aim from 22 yards.
Swansea continued to make life hard for the visitors as they pressed enthusiastically without the ball but clear chances were at a premium.
This was a meeting between the league's leakiest defence and the top away scorers. That was clear to see for the opening goal.
All Swansea’s hard graft in the early stages was wasted when Giroud thumped home from close range on 37 minutes after Ozil’s header from eight yards was sloppily dealt with by Alfie Mawson.
It was Giroud’s fifth goal in five games but Arsenal fans would’ve been worried to see their man hobble away following the goal and then replaced early on in the second half with an ankle injury.
The hosts thought they had a way back into the game six minutes after the opening goal when the referee blew as Ki Sung-yueng took a tumble in the area under a challenge from Laurent Kosceinly. However, the Swansea man was booked for simulation.
The second half was one-way traffic towards Lukas Fabianksi’s goal.
Ramsey had already forced the Swans goalkeeper into a brilliant stop when Cork's unfortunate mishap doubled Arsenal’s lead.
Iwobi tricked his way down the right flank and his cross caught the bottom of Cork’s studs and looped agonisingly over his goalkeeper and into the far corner.
Federico Fernandez blazed over from 12 yards on 64 minutes but his defensive counterpart Naughton showed him how it should be done three minutes - unfortunately it was at the wrong end.
Once again Iwobi caused panic in the Swansea defence with a tricky run down the left.
His cross found Naughton unaware and he clumsily turned the ball into his own net from six yards out.
The only aspect missing from this Arsenal performance was a Sanchez goal, but that came on 74 minutes as he scored his 14th of the season with a powerful finish from close range.
He celebrated wildly in front of the Arsenal fans, but his smile turned to a snarl minutes later when he was replaced by Danny Welbeck.
The Gunners are said to be in contract renewal negotiations with the Chilean, whose contract expires in 18 months, but he didn’t look in co-operative mood with his team-mates or his manager on the bench as he cut a frustrated figure with his overcoat pulled over his face.
Swansea: Fabianski (6), Naughton (5), Fernandez (5), Mawson (4), Kingsley (5), Ki (6), Dyer (6), Cork (5), Routledge (7), Sigurdsson (6), Llorente (6).
Subs: Fer (6), Borja (5), McBurnie (6).
Arsenal: Cech (7), Gabriel (6), Mustafi (7), Koscielny (8), Monreal (7), Ozil (7), Xhaka (7), Ramsey (6), Iwobi (7), Sanchez (8), Giroud (7).
Subs: Oxlade-Chamberlain (7), Lucas (6), Welbeck (6).
Man of the match: Laurent Koscielny