Carrick Rangers were for long spells the equal of their Premiership opponents Coleraine but it is the Bannsiders who have a slender one goal lead ahead of the rematch.
It was totally against the trend of play when Coleraine went in front in the 10th minute.
They won a corner which was floated over by Stephen Carson from the left flag and Stephen Dooley had the luxury of a free header and made no mistake planting it firmly into the back of the net from 12 yards out.
In the 33rd minute Rangers were awarded a free kick in a central position and Chris Wilkinson avoided the wall to deliver his low shot into the back of the net giving McCormick no chance.
After the referee cleverly allowed play to continue after a foul Rangers went ahead when Costello then fed the lively Kyle McDowell who danced around two defenders to slot the ball deftly past McCormick.
But in this eventful game Coleraine were back in it two minutes later when Darren Cassidy cut the ball back from the left just outside the penalty area and gave Richard Gibson who had come on as substitute for Jody Tolan had an easy tap in..
And then Coleraine then went ahead three minutes later when Davy Patton at the left of the 18 yard area slammed a daisy cutter straight into the net — a superb effort.
Hower Rangers were still not lying down and levelled again when McCormick miscued his clearance and hit it against Costello and then tried to bring the strike down but he rode the challenge and drilled it into the net.
With two minutes of normal time remaining Rangers hopes of what would have been a deserved a draw were dashed when an in-swinging corner from Carson was breasted into his own goal by James Forsythe.
Carrick Rangers: McCloskey, Watson, Wilikinson, McManee, Branniff, Paul Prenter, Irwin, Taggart, Costello, McDowell, Okainaya. Subs: Connor, O’Hare, Parker, Walsh, Forsythe.
Coleraine: McCormick, Beverland, Crossan, McLaughlin, McVey, Harkin, Cassidy, Shields, Tolan, Carson, Dooley. Subs: Neill, Ewert, Gibson, Lamont, Patton.
Referee: Simon Creany (Newtownards).