Two substitutions from Gary Holt made the difference as Falkirk came from behind to send Ayr out of the Ramsdens Cup 2-1 after extra time.
Bringing on Blair Alston and Jay Fulton as a pair helped bring the equaliser for Falkirk through Rory Loy, then a third change in additional time put teenager Scott Shepherd front and centre to head the Bairns into Thursday’s third round draw.
The manager caught everyone out by omitting Phil Roberts from the pool entirely, as well as the ill Stephen Kingsley, while switching Alston and Fulton with Craig Sibbald and Thomas Grant from Saturday’s bench.
Luke Leahy and Liam Dick were both given the opportunity to impress, and Leahy could have done with an early header after 11 minutes,
At the other end, Martyn Campbell went close with a header that Michael McGovern held well.
Going forward, Falkirk played everything through Craig Sibbald and the 18-year-old had an excellent first half hour. After good work on the left by Kyle Turnbull and Rory Loy, who switched play to the teenager, Sibbald sent an excellent throughball to Thomas Grant’s run that was just cut-out by Alan Lithgow.
Falkirk failed to heed the subsequent warning when Liam Dick allowed Craig Malcolm too much space after a poor clearance to send a shot skidding wide on 21 minutes and it was a similar scenario when the striker slammed the ball past McGovern shortly before the break.
Until then, the Bairns had been holding their own, though began to panic in the lead-up to the goal.
Gary Holt threw on Fulton and Alston for Conor McGrandles and Luke Leahy, and the change immediately worked wonders.
Falkirk were brighter going forward with five genuine threats going forward in the subs, Sibbald, Loy and Alston, and within minutes were level.
Fulton charged through and fired straight at David Hutton, and Blair Alston following up made a [poor connection with the follow-up. He did manage to prod the ball wide to Rory Loy who was left with the easy task of stroking into the empty net.
Time ticked away and Michael Moffat spurned a great chance with six minutes to go, slicing over from close range and Sibbald heading over from five yards at the other end from a great Kieran Duffie cross.
Ayr Captain Scott McLaughlin had a chance to win it with a 90th minute run into the box but elected to pass on to Malcolm and Turnbull did enough to divert the ball away and prompt extra time.
Ayr had the first chance of the additional period, but a brave slide by Ollie Durojaiye blocked Robbie Crawford’s shot and Michael McGowan’s subsequent shot spun wide.
Gary Holt threew caution to the wind, replacing his set-piece specialist Grant with flame-haired rookie forward Scott Shepherd after four minutes of extra time.
End to end football followed and Ayr left-back Gordon Pope smacked the crossbar with a powerful shot that bounced on the line and back into play, then Rory Loy nodded a Jay Fultopn free-kick onto the top of the bar.
McGowan flashed a shot across goal at the other end for Ayr in the first period but the tie was put to bed with Scott Shepherd’s 110th minute header.
The young forward was shepherding the ball out for a corner when he was crunched from behind by Alan Lithgow. The forward got his revenge though by glancing the set-piece from Jay Fulton across goal and into the net.