CLEVELAND -- There was no Game 2 comeback for the Toronto Raptors.

A rattled DeMar DeRozan, another sizzling three-point shooting night from Cleveland, and the Raptors dropped a 125-103 decision to the reigning NBA champion Cavaliers. They'll head back to Toronto down 2-0 in the best-of-seven Eastern Conference semifinal series.

Jonas Valanciunas had 23 points to top Toronto, while Cory Joseph had 22 and Kyle Lowry shook off a sprained left ankle in the third quarter to finish with 20. Serge Ibaka added 16 points. DeRozan finished with just five points, and didn't make a field goal until early in the fourth quarter.

LeBron James had 39 points, passing Kareem Abdul-Jabbar for second all-time in post-season scoring, and now trails only Michael Jordan. Kyrie Irving added 22 for the Cavs, who made 18 of their 33 three-point attempts to Toronto's five.

Two nights after dropping the series opener 116-105, Raptors coach Dwane Casey had predicted more fight from his players in Game 2. They traditionally rebound well from a loss, and are solid in Game 2s.

"We're better with our backs against the wall, when we get punched in the mouth," Casey had said. "Our disposition is better when we get smacked upside the head, so I think we'll respond, we'll play harder tonight. Whether that guarantees a win or not, I'm not going to say that. But I think we'll be a different team."

Yet, it was more of the same. Despite inserting Norman Powell and Patrick Patterson into the starting lineup to push the pace, the Raptors managed to dig themselves an early hole anyways. They managed to cut the Cavs' lead to single digits in the second quarter, but by the time Irving scored on a driving bank shot late in the third quarter, Cleveland waltzed into the fourth with a 99-73 advantage.

The Cavs twisted the knife in the fourth, taking a 30-point lead with 9:32 to play on a three-pointer from Channing Frye. Casey went to his bench soon after. As the final couple of ugly minutes ticked down, many fans had already left Quicken Loans Arena, which was a raucous sea of yellow T-shirts and white rally towels. A photo of Toronto rapper Drake was shown on the big screen during Raptors' free throws.

A frazzled DeRozan, who didn't score a field goal in Game 3 versus Milwaukee, was just 2 of 11 from the field, wrapped up for most of the night by JR Smith. The all-star tugged his shirt up over his face in frustration a couple of times.

There were some tense moments early in the second half when Powell crashed into Lowry's leg in a collision under the net. Lowry was down on the court for several minutes before limping to the locker-room, but returned moments later, driving to the hoop for a layup.

The Cavs shot 55 per cent on the night to the Raptors' 47 per cent. Toronto went just 5 of 17 from three-point range.

Ibaka got off to another slow start, missing his only four shots of the first quarter. The Raptors were clobbered 13-2 on the boards in the frame, and the Cavs took a 34-22 lead into the second quarter.

The Raptors had a mini 10-5 run midway through the second to pull to within nine points, but the Cavs responded with back-to-back threes and they took a 62-48 lead -- identical to Monday's Game 1 -- into halftime.

In last season's conference finals, the Cavs routed Toronto in Games 1 and 2 by a combined 50 points. The Raptors rebounded to take Games 3 and 4, eventually going down in six games.

Game 4 is Sunday in Toronto. Game 5, if necessary, would be Tuesday in Cleveland.