Porto come back down to earth
Portmarnock slumped to a disappointing defeat as they were brought back to earth following the previous week's 4-2 away win in Leixlip.
The form book suggested the points were there for the taking for Willie O'Leary's men after Glenville lost in mid-week at home to Leixlip - the same opponents who Portmarnock swept away a week earlier.
However, football isn't as simple as that and it was Glenville who opened the scoring after 20 minutes as their centre-half rose highest to head home a corner. The goal came slightly against the run of play, with Portmarnock starting the game with plenty of the ball without creating too much.
Shortly after that setback Portmarnock were dealt another blow as centre-back Darren Kelly was forced to leave the pitch after receiving a head injury.
Porto had started off with a 4-3-3 formation and following Kelly's injury O'Leary changed to a 3-5-2, with the lively left winger Cian McGregor coming in for the injured centre-back.
McGregor had an instant impact on the game as he attacked the Glenville full-back at will, causing havoc in the opposition defence. Portmarnock should have equalised when McGregor beat his man before teeing up Graham Rusk who headed over the bar when he really should have scored.
The equaliser did come moments later when Chris Burgess beat his man and ran to the byeline before pulling back the ball for midfielder David Sheppard to sweep the ball home. That proved to be the last meaningful action of a cagey first half, with both teams going in level at the break.
The second half followed a similar pattern to the first, with Portmarnock seeing plenty of the ball without creating too many clear-cut chances.
In the 70th minute disaster struck for the home side when a long ball from Glenville wasn't dealt with by the Portmarnock defence. The Glenville striker picked up the pieces before squaring the ball to his teammate who gleefully tapped home to spark celebrations in the away dugout.
Portmarnock piled on the pressure in the final 20 minutes, but as was the story of their day they failed to create any meaningful openings and it was Glenville who returned to Palmerstown with three points in the bag.
Portmarnock: Robbie Byrne, Callum Riches, Darren Kelly (Cian McGregor), Daniel Butler, Niall Kenny, David Shepherd Noel McGinty, Ross Moran, Graham Rusk, Keith Dawson, Chris Burgess.