Swansea City moved out of the Premier League relegation zone for the first time since November following a shock victory over Arsenal.
A horrendous error from goalkeeper Petr Cech allowed Jordan Ayew to score a tap-in which put the hosts ahead just after the hour mark, before Sam Clucas’ second goal made the result safe.
Mesut Ozil’s sensational pass had allowed Nacho Monreal to open the scoring for the Gunners, but Clucas levelled for Swansea within a minute at the Liberty Stadium.
Swansea earned back-to-back wins for the first time this season, while Arsene Wenger’s side have won only three of 13 Premier League away games this term.
Under new boss Carlos Carvalhal, Swansea have now lost only once in eight games and victory over Arsenal was their second successive win against a team in the top six.
Free-scoring Liverpool were blunted in the Swans’ previous outing at the Liberty Stadium and the hosts carried on that form as they dominated their visitors in the early part of the match.
Only a brilliant Aaron Ramsey tackle denied Alfie Mawson a tap-in from close range in the first half and an effort from Ayew looped over the bar off Mustafi with Cech wrong-footed and unable to act.
Mawson also shot just wide as Arsenal failed to clear a corner, before the England Under-21 defender provided the defence-splitting pass that allowed Clucas to score his first goal since he found the net at the Emirates in the reverse fixture on 28 October.
While that strike was worthy of praise, Swansea’s second goal was entirely down to deficiencies in the Arsenal defence.
Mustafi’s backpass proved awkward for Cech who sliced a clearance straight to Ayew and the Ghanaian slotted home from close range.
Clucas wrapped things up on 86 minutes, firing home after another lung-busting run from the impressive Ayew.