Queen’s Park deservedly forced a Hampden Park replay on Tuesday evening as they extended their rich run of form, which has brought only one defeat in the last 11 games.
Gus MacPherson’s men could even have won at the first time of asking as they more than held their own against their misfiring Championship opponents.
Queen’s showed no signs of inferiority and after only five minutes Ryan McGeever’s header from a Jamie McKernon corner was booted off the line by Brian Gilmour.
The Hampden amateurs underlined their menace seven minutes later with a Paul Woods shot which Greg Fleming blocked with his legs.
United hit back with a thunderous 25-yarder from Gary Harkins but keeper Willie Muir was equal to the shot with a super save to tip over.
McGeever almost gifted Ayr a chance with a stray passback which eluded Muir and slipped wide for a corner.
Ayr closed the first half with a downward header from Scott McKenna but it was well saved by Muir.
The visitors were looking more and more assured and Ayr’s anxiety grew as Conrad Balatoni sliced a Sean Burns free-kick over his own bar.
Ayr had penalty claims denied by referee Barry Cook when Robbie Crawford appeared to be shoved to the ground as he burst into the box.
Craig Moore, who was making his Ayr comeback after six months out, was replaced by teenager Craig McGuffie with 15 minutes to go.
Skipper Nicky Devlin tried to spark a late winner when he drove to the byline but his low driven cross was turned behind by McGeever.