David Scullion’s quick-fire strike settled this Danske Bank Premiership mid-table slog.
The result means that Alan Kernaghan’s Glentoran boys claw to within six points of the Bannsiders.
Glentoran got off to a dream start with Scullion converting after only three minutes.
Skipper Marcus Kane sent Curtis Allen scampering free on the left and when he drilled a low cross across the face of the goal, little Scullion just couldn’t miss.
After soaking up the early pressure the Bannsiders began to ask a few questions at the other end. Big James McLaughlin found himself with time and space and let fly from 30 yards that Elliott Morris did well to beat away.
It was the Glens who almost grabbed a killer second goal just before the interval. Teenager Jonathan Smith held his head in frustration after curling in a drive from the edge of the box that John did superbly well to paw away.
Youngster Jamie McGonigle almost had Coleraine level on the hour. Having cut in from the right, his shot was superbly pushed away by Morris and Ruairi Harkin pulled his shot wide.
When the Bannsiders did eventually get the ball into the net when McCauley finished off a knockdown form substitute Sammy Morrow, referee Gregg disallowed the effort having spotted the scorer in an offside position.
Coleraine’s David Ogilby then flicked a Ruaidhri Higgins free kick wide.
Glentoran: Morris, Holland (Gibson 21), Kane, Magee, Addis, Rice, Caldwell (Morrow 69), McCullough (McCaffrey 79), Allen, Smith Scullion.
Subs not used: Hogg, Birney.
Coleraine: Johns, Beverland, Mullan, Higgins, Ogilby, McCauley, Harkin, Brown, McGonigle, McLaughlin (Kanswicher 75), Parkhill (Morrow 50).
Subs not used: Doherty, Watt, Edgar.
Referee: Steven Gregg (Ballyclare).