Burton O'Brien fired home the winning goal from 35 yards

A 1-0 win booked a Scottish Cup semi-final place against his former club, Celtic, on 11 April.

"It was a fantastic result on Sunday, but this was a much grittier performance," said Hay.

"They put so much into Sunday and we probably drained the last piece of juice out of them tonight."

The CIS Cup was Livingston's first major trophy and now they have the chance of a cup double that would be a rarity for a club outwith the Old Firm.

Their team's progress has been achieved despite the club going into administration in February.

We fell short where we had feared, in the final third Aberdeen boss Steve Paterson

"For a team like Livingston to win on Sunday and then have the chance of another final is nothing short of miraculous," said Hay.

"We had to dig deep for that. Aberdeen had a lot of possession without opening us up much.

"Marvin Andrews was outstanding for us in defence."

Victory was secured by a 35-yard finish by Burton O'Brien that caught goalkeeper David Preece out of his goal.

"It was an unbelievable goal," said Hay. "To think about that and then to execute it was just great."

Midfielder O'Brien was more matter-of-fact about the winner.

"Nine times out of 10, the goalkeeper's clearance would have flown over my head," he said.

"I just took a touch and gave it a smash."

O'Brien acknowledged that he and his colleagues had still not recovered from their exertions at Hampden.

"The legs had gone before this game, but we are through it and it has been a great week for Livingston."

Andrews, voted man of the match, said it was an "inner belief and desire" to win that had pulled them through and would stand them in good stead in the semi-final against a Celtic team in excellent form and running away with the league title.

Match report: Livingston 1-0 Aberdeen

"There is no way that we should be afraid," said the defender. "We will give it our best shot."

Aberdeen manager Steve Paterson again lamented his side's lack of firepower up front in a game they dominated.

"I could not fault my players for effort," he said.

"But we fell short where we had feared, in the final third, as we lacked the guile to break Livingston down.

"Livingston's back three defend their goalkeeper magnificently and I think they are the best in Scotland outwith the Old Firm.

"I think we could have played another 90 minutes without creating anything."