Ayr United's bid to complete an unlikely play-off comeback went up in smoke on a gruelling night at Somerset Park.
Ruthless Partick Thistle showed no mercy as they ran in another five goals to add to their first leg advantage as Ayr were forced to play for more than an hour without talisman Dipo Akinyemi following a red card flashpoint in the first half.
Scott Tiffoney bagged a double while Jack McMillan and Steven Lawless also got on the scoresheet on a bitterly disappointing night for Ayr, who had hoped to launch a stirring fightback in the wake of last Friday's Firhill reverse.
They made four changes from that side with Akinyemi returning alongside Nick McAllister, Reece McAlear and Sam Ashford.
And in front of a crackling atmosphere they began with their tails up and almost hit the front inside four minutes when McAlear forced a smart low stop from David Mitchell.
But any faint hopes of a fightback were quickly extinguished as Thistle killed the tie within the opening ten minutes.
The Jags got in behind Ayr's defence and when Ross Docherty crossed for Aidan Fitzpatrick, his shot was saved - only for McMillan to slam home the rebound.
Ayr's night rapidly went from bad to worse when Akinyemi was given his marching orders before the half hour after being drawn into a spat with United old boy Aaron Muirhead near the halfway line.
When the striker wrestled himself clear from Muirhead's grapple, he responded by thrusting his arm at the defender, resulting in ref Colin Steven flashing the straight red card.
And within seconds Thistle had rubbed extra salt in the wounds as they raced to the other end with Fitzpatrick crossing for Scott Tiffoney to turn home at the backpost.
Ayr could offer little resistance as the tie entered the second half and when McMillan teed up Tiffoney, he had the easiest task to turn home the third goal of the night.
Lawless knocked home a fourth just after the hour mark as Thistle turned on the turbo boost and left Ayr desperately looking for the full time whistle.
But the final agony was added in stoppage time when Kevin Holt beat Charlie Albinson to a corner and nodded home to make it five.
