EDMONTON — Signing Trevor Harris as a free agent to back up Henry Burris at quarterback has already paid big dividends for the Ottawa Redblacks.

Harris came in as relief and passed for three touchdowns as the Redblacks beat the Edmonton Eskimos 45-37 in overtime on Saturday in a rematch of last year's Grey Cup.

Redblacks starting quarterback Burris banged his right hand on the helmet of an opposing player and went down the next play during a handoff exchange in the third quarter and left the game, opening the door for Harris.

"That's why we signed the guy," said Ottawa head coach Rick Campbell of bringing Harris in from Toronto.

"He is a pretty cool customer and doesn't get phased out there. He is a true team player. Both he and Henry have been excellent in that they both want the team to win and good on him for stepping in and being ready to play. It's a huge comfort knowing we have two guys who can step in and get it done.

Harris completed a 12-yard touchdown pass to Brad Sinopoli to start the extra session and Ottawa kept the Eskimos off the board in their attempt at a response. He finished the game 17-of-19 passing for 292 yards. Burris was 23-of-31 for 258 yards and a TD before getting hurt.

Burris was also impressed with the performance of Harris when he went down.

"There was a little swelling from hitting that helmet and I just wanted to make sure there was no additional swelling, but Trevor was doing a good job and there was no need for me to rush back," he said. "He is a great young kid who has a bright future ahead of him. This is only the beginning for him."

It was the first win for an Ottawa team in Edmonton's Commonwealth Stadium since 1983.

"I'm not hanging my head, I don't think anyone in this locker-room is hanging our head about this," said Eskimos head coach Jason Maas.

"If I was mad about anything in this game, it was we had five 15-yard penalties and that's points for the other team every time you do that, generally. That's what pisses me off, but at the end of the day, we learn from that."

The game started slow, as Ottawa held a 3-1 lead at the end of the first quarter.

Edmonton got a field goal before Ottawa scored the game's first touchdown. Burris made a four-yard pass to Kienan Lafrance and added a two-point convert for an 11-4 lead.

The Eskimos tied the game when Mike Reilly found John White for a 27-yard passing major, before Ottawa kicker Chris Milo booted a 45-yard field goal to make it 14-11 at the half.

Reilly went 28 for 40 for 383 yards and one TD.

Edmonton's special teams came up big early in the third as Reuben Frank blocked a punt and then was able to fall on it in the end zone for the touchdown.

It was then the defence's turn soon after as Odell Willis picked off Burris at the Ottawa 12, leading to a Sean Whyte field goal.

The tough stretch continued for the Redblacks when Burris got hurt and left the game. However, Harris came in off the bench and made an immediate impact, throwing a 71-yard TD strike to Chris Williams to knot the game back up.

Harris did it again on the next possession, finding Williams for a 37-yard touchdown pass. Edmonton came back with a field goal to cut the lead to 28-24 heading into the fourth quarter.

The two teams traded field goals early in the fourth, with Ottawa then adding another midway through the quarter to make it 34-27.

Edmonton tied the game up again with four minutes left when Reilly completed a 64-yard pass to Derel Walker that set up a two-yard pitch to White to make it 34-34.

The Eskimos then moved the ball into range for Whyte, who kicked a 39-yard field goal with 54 seconds remaining.

However, the Redblacks marched back up field and Milo was able to kick a career-best 55-yard field goal with no time left on the clock to send the game to overtime.

"He drilled that thing," Campbell said. "I think it would have been good from 60."

Ottawa remains on the road in Week 2, travelling to Montreal to face the Alouettes on Thursday. The Esks have a bye next week.