Two goals midway through the second half tipped the balance in favour of Glenavon over Glentoran at Mourneview Park.
In a quiet opening to the game both sides were limited to little more than half chances with Jay Donnelly just failing to get a strong enough touch to a Marcus Kane ball from the left while, at the other end, Michael O'Connor could only fire straight at Rory Brown.
However, the deadlock was broken midway through the first half in Glentoran's favour when Conor McMenamin broke into the box on the left before finding Rory Donnelly who finished from close range.
The visitors looked likely to double their advantage after the break with Ciaran O'Connor firing just over from 20 yards while Jay Donnelly rattled the crossbar soon after from a similar distance.
But Glenavon levelled on 70 minutes through Robert Garrett who dispatched a superb 25-yard right foot drive beyond Brown.
Then, just three minutes after that, Matthew Fitzpatrick bagged what proved to be the winner after driving the ball home from six yards.
Glenavon: Hyland, A. Doyle, Byrne, Purkis, Campbell, O'Connor, McCloskey, Douglas, Singleton, Garrett, Ward subs J. Taylor (not used), Harmon (not used), Fitzpatrick (replaced Purkis 62), Norton (replaced Douglas 67), McCaffrey (replaced Byrne 62), O. Taylor (not used), Rea (not used)