Swansea moved to within two points of Sky Bet Championship leaders Norwich with a 2-0 victory over 10-man Luton.
Luton's inconsistent form continued as they suffered their second defeat in a week on Welsh soil to remain 12th.
Swansea could now go top on Tuesday if they beat former leaders Bournemouth and other results go their way.
Steve Cooper made five changes to the Swans side beaten at Middlesbrough in midweek, with captain Matt Grimes returning to the starting XI alongside Yan Dhanda after his consolation goal on Wednesday night.
Nathan Jones returned to South Wales a week on from Luton's 4-0 humbling at the hands of Cardiff.
The Hatters recovered with a stunning victory over high-flying Norwich in the first competitive match attended by supporters since the Covid-19 outbreak in midweek.
After conceding after four minutes on their last trip to Wales, Luton found themselves behind inside the second at the Liberty Stadium.
Ayew combined with Cullen on the edge of the penalty area before laying the ball off for Roberts, who fired a left-footed shot past goalkeeper James Shea via a deflection off Dan Potts for his second goal in three matches.
The Hatters launched a response and should have found the equaliser in the 26th minute after Ayew's wayward pass allowed Jordan Clarke to send a low cross into the box.
Luton centre-half Matty Pearson was shown a yellow card for a cynical late foul on Ayew on the hour mark.
He then received a second yellow and subsequent red card 10 minutes later after making contact with the head of Marc Guehi with an attempted overhead kick at a corner.
The 10 men of Luton would have been level moments later had Ayew not got back on his own line to clear Glen Rea's header away at the last.
And the Ghana striker made his mark at the other end of the pitch in the 90th minute when he picked up the ball from Kasey Palmer, turned to drive at goal and unleashed a powerful left-footed shot into the bottom corner.