After Dargo's double in the first half, it should have been plain sailing in the second half and it looked as if it would be with the striker and Michael Higdon going close to extending the lead. However, a Mark Roberts penalty changed the course of the game completely and in the end we were clinging on once again. This time, we managed it.
With Paddy Cregg injured, there were always going to be changes and he was replaced by Dargo, while Jure Travner dropped to the bench to be replaced by David van Zanten. It was an odd change and it meant Lee Mair continued at leftback. Vanzy moved to right midfield, with Paul McGowan dropping back to midfield.
Nearly 6,000 fans crammed in to Somerset Park and many Saints supporters were a apprehensive considering our recent league form and Ayr's giant killing abilities. However, after just six minutes a van Zanten pass somehow evaded the Ayr defence and Dargo switched the ball to his left foot before drilling a low shot past keeper David Crawford.
That should have settled us down, but it seemed to have the opposite effect. Mair struggled to win a header at left back, the passing was poor and there was some poor defending, with Paul Gallacher causing chaos on at least one occasion. The bright spot was Darren McGregor putting in another fine display - although we'll come on to his mistake later.
Ayr were causing the Saints defence problems but it's hard to think of them really doing much in the first half. Meanwhile, we were lucky to stay with 11 men when Higdon was only booked for flattening former Saint Eddie Malone. Had it been the other way around we'd have been screaming for a red card.
Right on half time it looked like we were well in control when Higdon slipped the ball through to Dargo and he charged forward. He evaded Crawford and seemed to have run the ball out of play, but somehow managed to cut back and beat two defenders before putting the ball away.
We were in easy street and it should have been party time when Dargo was sent in behind early in the second half but shot wide. Great work from McGowan set him up again but he failed to score before Higdon had a header saved by Crawford.
Then it all went wrong. A great block from Gallacher or McGregor came at the expense of a corner and when it was swung in, McGregor was deemed to have handled. Roberts stepped up to score and bring Ayr back into the game.
They began throwing everything at us, while a decision to replace Dargo with Kenny McLean did not go down well with the travelling support. McGowan injured himself trying to score and was replaced by Hugh Murray, leaving an increasingly lazy looking Higdon up top on his own.
Gallacher rescued us on a couple of occasions, most notably when a cross was missed and Stuart Bannigan somehow prodded the ball into the keeper's arms when he should have scored - although he seemed miles offside.
Fortunately, that was as close as Ayr got and we should have finished things off when McLean sliced an effort wide. In the end it was irrelevant as we made it through to the quarter-finals.
The first half was fine, the start of the second half was fine but when they pulled one back we went to pieces. Again we had an odd line-up and odd subs, but the important thing was to avoid an upset - and we did.
The Hampden dream is still alive.
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