A fine low strike from Alan Forrest, coming back to haunt his old club, added gloss to the scoreline just prior to the break.

Ayr managed to stem the bleeding in the second period but a miraculous comeback was never on the cards and Livi – even without a manager – are now just one game away from Hampden.

Martindale resisted the temptation to make wholesale changes, with Matej Poplatnik, Josh Mullin and Fitzwater replacing Jay Emmanuel-Thomas, the suspended Jason Holt and Ciaron Brown from the side which lost to St Mirren last weekend.

And Livingston took just 55 seconds to explode from the blocks and claim the lead, with a sumptuous delivery from Mullin glanced into his own net by the unfortunate Chalmers.

Livi doubled their advantage when Fitzwater latched onto a loose ball in the penalty area and lashed a low drive beyond Viljami Sinisalo, via a slight deflection off Innes Cameron.

With Ayr visibly reeling and in a shambolic state whenever a cross was put into their box, Martindale's men made it three courtesy of a bullet header from Fitzwater, who had not scored for the club before this game.

The Honest Men managed to temporarily shut up shop despite Jon Guthrie, Mullin and Fitzwater – seeking to claim the match ball – all threatening.

But Livingston did extend their advantage on the cusp of half-time when Forrest got in on the act against his former employers, latching onto a Nicky Devlin delivery and firing a clinical low drive beyond the shell-shocked Sinisalo.

Forrest's old Ayr team-mates will have been acutely aware of his qualities but were powerless to stop him after the break as he surged forward and unleashed another ferocious effort which drifted narrowly wide.

However, that was as close as Livi came to rippling the net as they visibly took their foot off the gas and coasted into the last eight.