Colin Nixon's two second-half goals helped take some of the pressure off Scott Young as Glentoran came from behind to beat bottom club Glenavon.
Glenavon took the lead on six minutes as Andy Graham's deflected shot flew past Elliott Morris.
Gary Hamilton levelled for Glentoran on 34 after woeful Glenavon defending.
Nixon's two goals after half-time put Glentoran in control and Glenavon's Brendan Shannon was sent-off late on after pushing referee Arnold Hunter.
Under-pressure Glens boss Young made four changes from last week's home defeat by Ballymena with Jamie McGovern and Sean Ward dropping out on the defence, Richard Gibson demoted to the bench and David Howland out because of suspension.
Johnny Taylor and Jimmy Callacher were drafted into defence, with Richard Clarke starting in midfield and 18-year-old Kyle Cherry handed his first league start.
Glenavon were minus Mark Haughey, who suffered a broken leg in the club's first league win of the season against Coleraine last weekend.
The home side were rewarded for an enterprising start as Graham's deflected shot flew past Elliott Morris after the Glens defence had failed to clear a Kyle Neill free-kick.
After Graham went close again for Glenavon, Glentoran levelled on 34 minutes as Hamilton poked home from close range after some woeful defending by the Lurgan Blues.
It was Hamilton's 100th goal for the Glens.
A minute later, youngster Cherry drilled inches wide after a weak O'Hare punch although Taylor came to the Glens rescue before the break with a brave header to stop a Shannon piledriver from hitting the net.
The key period of the match was the 15 minutes after half-time as veteran defender Nixon struck two goals.
Glenavon's defence went to sleep as Stephen Carson ran unchallenged before setting up Nixon to score with a superb cutback.
Nixon scrambled in the third goal three minutes later after O'Hare had brilliantly saved an initial shot.
Kelbie wasted a chance to pull back a goal for Glenavon as he was let down by a poor first touch but Carson almost extended Glentoran's lead with a fierce shot at the other end.
Glenavon were reduced to 10 men in the closing stages after Shannon stupidly pushed referee Arnold Hunter following the official's admittedly harsh decision to give the Glenavon man a yellow card.
Gibson should have made it 4-1 in injury-time but was denied by a superb O'Hare save.