Ayr finally found the way to goal at Ochilview as a grandstand comeback won three points against Queen's Park.
United were forced to come from 2-0 down after a tardy first half left them with a mountain to climb.
But Dipo Akinyemi's first goal for the club, followed by a captain's header from Sean McGinty, set up a huge finish as Akinyemi then buried a stoppage-time penalty to win it.
Lee Bullen had stuck with the same team that opened the Championship season with a goalless draw against Arbroath.
But they didn't look nearly as threatening as last week's version, with Queen's dominating possession in the early stages.
And the Spiders took a deserved lead with the game 17 minutes old when a simple set piece proved Ayr's undoing.
Dom Thomas was creator with a corner from the right and Simon Murray had the freedom of Ochilview to climb and head home from six yards.
Ayr continued to be their own worst enemy and duly fell two behind just before the half-hour mark.
Queen's were once again given far too much time and space in the final third and, when the ball eventually found its way to Thomas, he curled home a brilliant finish from 20 yards.
That finally woke Ayr from their slumber and Fraser Bryden almost got them back in it with a low header well saved by Calum Ferrie.
The young striker should then have scored before the break when clean through but he blazed over the top.
Bullen made a double change at the interval with Mark McKenzie an Daire O'Connor replacing Bryden and Jayden Mitchell-Lawson.
And the changes had an immediate impact with McKenzie playing in Akinyemi to fire home his first Ayr goal in front of the travelling support.
United were almost caught cold at the other end when a Murray shot was creeping in the bottom corner but Charlie Albinson got down to keep Ayr in it.
Ayr were proving a different animal in attack, though, with McKenzie and O'Connor adding a new dimension and McKenzie drew a great stop from Ferrie before O'Connor fired inches over as they threw everything at a leveller.
Spiders boss Owen Coyle reached for his bench to stem the tide and called on Nigerian international defender Stephen Eze to try and shore up their backline.
But it did little to change the pattern of play and Ayr finally forced the equaliser when McGinty rose to bullet home a header from a Ben Dempsey corner.
And just as it looked like Ayr would have to settle for a point, they won a penalty deep in stoppage-time when Charlie Fox handled in the box and Akinyemi stepped up to ram home and send the travelling support wild.
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