Setanta Cup - Drogheda Utd 2 Derry City 1:An Eamon Zayed goal four minutes into stoppage time at the end of this keen encounter saw defending champions Drogheda book their place in the last four.
Having fallen behind to a first-half goal and played second fiddle to their opponents for the opening 45 minutes, United were the better side in the second period and just about deserved their victory.
Derry went in search of a goal right from outset and went very close to opening their account twice in quick succession.
Killian Brennan's cross from the left found Ruaidhri Higgins, whose shot was punched out by goalkeeper Mikko Vilmunen to Greg O'Halloran, who saw his snap shot pushed out for a corner.
Almost immediately Derry won a free on the right which Brennan floated into the box for Peter Hutton, who glanced his header wide.
It was 25 minutes before Drogheda threatened the Derry goal when Paul Keegan's quick free picked out Zayed, but his header flew narrowly wide.
The visitors struck right on the half-time whistle when Higgins's corner on the right was only cleared to the edge of the box where Kevin Deery was on hand to send his shot through a crowded goalmouth to the net.
Ten minutes into the second half Drogheda won a corner on the right which Paul Keegan swung over for Gavin Whelan to guide his header back across the box for Zayed who volleyed over from 15 yards.
With 65 minutes on the watch Derry pushed down the left flank and Sean Hargan's cross fell to Mark Farren who lifted the ball over the bar from six yards.
Drogheda were back in the match in the 69th minute when Zayed pushed the ball out to Whelan on the right the penalty area. Whelan's shot was too hot for Pat Jennings as he spilled the ball to Tony Grant who was perfectly positioned to score.
A late Derry flurry saw Vilmunen tip Deery's free to safety, Farren head narrowly wide and Higgins test the alert net-minder from 25 yards.
Just when it appeared the game would end in a draw a long ball towards the Derry box saw Jennings race from his line and attempt a headed clearance, but the ball spun into the path of Zayed who guided his header to the empty net.
Linfield will face Cork City in the semi-finals on Monday, April 30th, after the Belfast club clinched first place in their group last night.
The visitors got off to the perfect start when they scored after seven minutes. Thomas Stewart, who had missed an earlier opportunity, received a pass and beat a couple of defenders before firing his shot low into the bottom corner from just inside the box.
Glentoran looked a much more determined side but they rarely troubled the Linfield goal until the awarding of a penalty three minutes before half-time.
Chris Morgan did not appear to be causing too much danger, but a combination of Kris Lindsay and Pat McShane brought him down and, from the spot, Kyle Neill made no mistake to level the scores.
The sides were on level terms for 13 minutes before Linfield grabbed what turned out to be the winner 10 minutes after the break.
Stewart's through ball broke the offside trap and Peter Thompson raced through to slide the ball under Elliott Morris and into the net.
DROGHEDA UTD: Vilmunen, Lynch (Whelan, 11 mins), Webb, Gray, Robinson, O'Keeffe (Grant, 15 mins), Shelley, Byrne, Zayed, Keegan, Cahill.
DERRY CITY: Jennings, Hargan, Hutton, Rogers, Higgins, McHugh, Brennan, Oman (McCallion 37 (Beckett, 88 mins), Deery, Farren, O'Halloran (Molloy, 13 mins).
Referee: D Malcolm (Belfast)
GLENTORAN: Morris, Ward, Simpson, Leeman, Neill, Browne (Halliday, 67 mins), Fitzgerald (Berry, 62 mins), Carson, McMenamin (Hamilton, 86 mins), Morgan, Hill.
LINFIELD: Shannon, Douglas, Lindsay, Bailie, McShane, Dickson (Mouncey, 65 mins), Mulgrew (Garrett, 79 mins), Gault, McCann (Kearney, 73 mins), Stewart, Thompson.
Referee: D McKeon (Dublin)