Cliftonville moved back into third place in the Irish Premiership as goals from Jay Donnelly and Stephen Garrett sealed victory away to Glentoran.
Donnelly struck in the sixth minute, latching onto a George McMullan through ball to slot past keeper Elliot Morris.
Cliftonville, who had lost their last two, doubled their lead in the 57th minute when Daniel Hughes played in Garrett who chipped over Morris.
This defeat leaves Glentoran with only six points out of a possible 24.
Cliftonville leapfrog Glenavon in the league table but remain 10 points behind leaders Crusaders.
Big result for Lyttle
Reds manager Gerard Lyttle will be a happier man after his side's first league win at the Oval since 2011.
Lyttle had been critical of his players' workrate following their 3-1 home defeat at home to Coleraine on Saturday.
Donnelly's 15th goal of the season gave the League Cup winners the perfect start on six minutes.
Curtis Allen twice went close for Glentoran but they were hit by a second Cliftonville goal skilfully finished by Garrett.
What they said
Glentoran manager Alan Kernaghan: "We gave away an early goal but responded well and if it had not been for their goalkeeper we could have been 3-1 up at half-time.
"But in the second half we were spectators and were taught a real lesson.
"I cannot fathom the differences in our performances. It is frustrating because I know I have a good set of players here."
Cliftonville manager Gerard Lyttle: "The players' attitude was brilliant and I have to applaud them.
"We were disappointed with Saturday's performance and we wanted to show that we care."