All the goals came in the second half as Glentoran overpowered Ballymena United at the Oval.
Jim O'Hanlon stroked in the opener in the 66th minute after Jordan Stewart had persevered to keep the ball in.
Top scorer Curtis Allen controlled with one touch before poking in the second for his ninth of the season.
An unmarked Stewart made it 3-0 from substitute Fra McCaffrey's cross and the highly-rated teenager scored again with a left-foot finish near the end.
Glens boss Eddie Patterson felt it was a perfect response after their shock County Antrim Shield exit at home to Bangor.
"We were abysmal on Tuesday night and let everyone at the club down," said Patterson.
"We wanted to put that right and we did.
"I am absolutely delighted, we played very well and deserved it."