Glentoran claimed the points at Glenavon thanks to well-taken goals by David Howland and David Scullion.
Howland fired a superb volley into the roof of the net after Calum Birney had played the ball back into the danger area in the 20th minute.
After the break, Stephen McAlorum did well on the right before playing over for Scullion to tap in at the far post.
Glenavon got back into it when Gary Hamilton's corner was touched in by Andy McGrory at the back post.
In a frantic finish, Glentoran's Jordan Hughes run through but saw his low shot come off the upright.
"We dominated the first half and Glenavon were lucky to be only a goal down at the break," said Glentoran manager Eddie Patterson.
"It was great work for Stephen McAlorum for the second goal.
"For the last 15 to 20 minutes we struggled a bit with Glenavon's long ball tactics.
"We have a few players to come back into the team and missed the likes of Jay Magee and Richard Clarke."
DANSKE BANK PREMIERSHIP RESULTS
Coleraine 2 (Lowry 62, Tommons 76)
Portadown 2 (Twigg 44, Braniff 70)
Crusaders 1 (Adamson 55)
Ballymena United 2 (Dolan 77, Liggett 89)
Dungannon Swifts 1 (Hazley pen 19)
Ballinamallard United 0
Glenavon 1 (McGrory 77)
Glentoran 2 (Howland 20, Scullion 56)
Linfield 2 (Knowles 32, A Burns 68)
Cliftonville 4 (Gormley 28, 30, O'Carroll 76, 92)