An early goal by Mark McKenzie moved Ayr United to within a point of Dunfermline Athletic in the Scottish Championship.
The win also gave Scott Brown victory over his former Celtic manager, Neil Lennon.
Dunfermline went into the game having enjoyed a stronger start to the campaign, but their chances of hauling themselves level were hampered when Jeremiah Chilokoa-Mullen was shown a second yellow.
And although Ayr also finished with 10 men, Dylan Watret being dismissed in stoppage time, the visitors held on to seal victory.
