Promoted side beat Arsenal at their own game, controlling possession with precision passes and allying it with enough cutting edge to claim victory.
Swansea City show Arsenal verve to dent Gunners' top-four chances
Swansea provided an exhibition in possession, playing an Arsenal-like passing game with familiar excellence and allying it with a cutting edge to claim the biggest scalp of their Premier League lives.
In the process, they damaged Arsenal's hopes of a top-four finish.
This is a side with spirit, responding admirably when they trailed to the inevitable Robin van Persie goal and immediately when Theo Walcott had restored parity. Danny Graham's subsequent winner was taken with the accurate assurance that has become Swansea's hallmark.
"I'm very proud," said Brendan Rodgers, the manager. "The journey we have been on in the last 18 months has been incredible. To beat a top team was fantastic and the players were brilliant."
They have acquired a formidable home record by dint of retaining possession as Arsenal found themselves in the unusual position of being out-passed. Joe Allen and Leon Britton seized control of the midfield with their technical skill to provide the platform for the creation of a host of chances.
"The players show courage to pass the ball," Rodgers said. "I have great belief they can play and pass."
Their first goal, however, came coated in controversy. Nathan Dyer was electric throughout, short, sharp and skilful. Yet when the winger spun, turned and clashed legs with Aaron Ramsey, the Arsenal midfielder was unlucky to be adjudged the offender.
"I still don't understand where the referee found the penalty," complained Arsene Wenger.
Nevertheless, Scott Sinclair, one of the division's premier spot-kick specialists, converted from 12 yards. It cancelled out Van Persie's 20th goal in as many away league games, taken with enviable calm after Andrey Arshavin, in his only meaningful contribution, provided the pass.
Arsenal could have led again, Steven Caulker clearing Ramsey's shot off the line. But it amounted to an afternoon of misfortune for the Wales captain; he was dispossessed by Allen for Swansea's second goal, his international team-mate then finding the unmarked Dyer. He angled his shot back across goal to score for the third successive game.
Arsenal responded. Walcott raced on to Johan Djourou's defence-splitting pass to score his first goal since October with a dinked shot.
Yet Rodgers had recognised Arsenal's defensive frailties and set about exploiting them. It was a sign of Swansea's ambition when he brought on Gylfi Sigurdsson for Kemy Agustien at the break.
His reward came as Arsenal were distracted by Walcott's strike. The Icelander sent Graham clear with an incisive pass and the top scorer finished superbly.
For Arsenal, failing to play offside, it was another indication they were slack at the back.
"Defensively, we made some mistakes that we should not have done," Wenger said. "In the last games we have made mistakes that are difficult to explain. It's unbelievable."
Per Mertesacker endured a particularly torrid time, which was compounded when he was guilty of a glaring miss at the other end and promptly substituted. Another culprit was Thierry Henry, whose misplaced pass preceded Graham's goal.
That apart, his return to the Premier League after a five-year absence was demoted to a subplot on a memorable day in West Wales.
While Arsenal have flaws to address, these particular Swans are flying.