Glentoran hit five goals against Ards to move to the top of the Irish Premiership table on goal difference.
David Scullion's lob over keeper Graeme McKibbin put Glentoran into a fourth-minute lead.
Calum Birney volleyed in from a Richard Clarke corner on 57 minutes and Clarke headed in deftly at the near post to make it three.
Two substitutes, Jordan Hughes and Niall Henderson, got on the scoresheet as Glentoran finished well.
The scoreline means Ards, promoted as winners of Championship One, fall to the bottom of the table, below the other promoted club Warrenpoint Town on goal difference.
At the top, Glentoran are tied on nine points with Cliftonville and Ballymena United.
It was a deserved win for Eddie Patterson's men as they outclassed Ards.
Patterson will feel his side should have been more than one up at the interval.
They got the dream start when Scullion, in his second spell at the Oval, ran on to a delightful through ball by Jimmy Callacher to lift his nice finish over McKibbin.
The Glens did have chances before the break but failed to make them count while Craig McMillen headed over for Ards.
The goals did flow after the break, however, enabling Glentoran to enjoy their top spot before taking on Crusaders in their next match on Saturday, again at the Oval.