The Sarnia Sting (12-14-0-0) fell 5-3 to the Firebirds (16-10-0-0) in Flint on Sunday afternoon for their sixth loss in their past eight games.
Jacob Perreault led the way for the Sting with two goals. Sam Bitten also scored, while Jamieson Rees dished out two assists.
The Sting were up 1-0 after one, and 2-0 early in the second period.
Flint scored a pair of second period goals to tie the game 2-2, and then pulled ahead 4-2 late in the third.
Sarnia edged closer at 4-3, but the Firebirds sealed the victory with an empty net goal with nine seconds remaining.
Vladislav Kolyachonok scored twice and had an assist for Flint. Jake Durham and Connor Roberts each had a goal and an assist, and Brennan Othmann had two helpers.
Ben Gaudreau stopped 34 of 38 shots in the Sting crease. Flint's Anthony Popovich turned aside 39 of the Sting's 42 shots on goal.
The Sting scored twice on six powerplay chances, and the Firebirds capitalized on one of three opportunities.
Sarnia is now 8th place in the OHL's Western Conference with 24 points.
The Sting are back in action on Friday night at home to Saginaw for the annual Teddy Bear Toss game.
They'll head to Niagara on Saturday and Erie on Sunday.
As always, you can hear all of the action live on 103.9FM and 1070AM CHOK.