Late drama saw Swansea extend their unbeaten league away record with an equaliser deep into stoppage-time to make it 2-2 at Sheffield Wednesday after conceding moments earlier.
Wednesday went close to taking the lead inside the fourth minute when a corner from Kadeem Harris picked out Jacob Murphy and his first-time shot was saved by Freddie Woodman, who pushed the ball onto his left-hand post.
Atdhe Nuhiu also threatened with a curling 20-yard effort which was not far off target.
As the hosts continued to apply early pressure, Woodman parried Steven Fletcher's header and Nuhiu looked to get on the end of the rebound but Ayew was on hand to head clear.
The visitors survived another scare on the half-hour mark when Kieran Lee's cross found Fletcher whose header came back off Woodman's left-hand post.
Swansea took the lead against the run of play when Westwood failed to deal with a Matt Grimes corner and Ayew (32) pounced on the loose ball, smashing it into the net from close range.
Wednesday threatened soon after the restart when Fletcher's searching low cross from the left picked out Murphy, running in at the near post, who shot wide under pressure.
Nuhiu failed to make proper contact after stooping to meet Murphy's free-kick, glancing the ball wide.
Wednesday hit the woodwork for a third time just after the hour-mark. Fletcher's header from a Harris cross was saved by Woodman and Murphy smashed the loose ball against the keeper's left-hand post.
The hosts had a strong appeal for a penalty turned down after Nuhiu appeared to be hauled to the ground inside the area.
Swansea threatened twice in quick succession with Ayew putting a header wide from a Wayne Routledge cross and Wilmot heading against a post.
Westwood made a fine save down to his left to keep out a shot on the turn from Ayew.
Wednesday equalised when Adam Reach's low drive was parried by Woodman and Lee put the ball across the face of goal for Forestieri (81) to finish from close range.
Fox struck in time added on after Iorfa headed down following a corner before Wilmot equalised with a far-post header following a Grimes corner.