CLEVELAND — The Toronto Raptors rode a wave of momentum into Cleveland on Wednesday.

But by the merciful end of an atrocious Game 5 effort, it was tough to believe the Raptors had ever beaten the Cavaliers at all.

Cleveland's trio of Kevin Love, LeBron James and Kyrie Irving combined for 71 points as the Cavaliers thoroughly trounced the Raptors 116-78 to take a 3-2 lead in the NBA Eastern Conference finals.

"They kicked out butts. That's the bottom line," coach Dwane Casey said in the post-game news conference, over the cheering of a Cavs fan out in the corridor.

DeMar DeRozan had just 14 points, while Kyle Lowry had 13, but no other Raptor scored in double digits in Toronto's worst performance of these playoffs. Jonas Valanciunas returned from his ankle injury to score nine points in 19 minutes.

The Raptors were coming off back-to-back victories at the Air Canada Centre, infusing fans with a glimmer of hope for an historic NBA finals appearance. But the Cavaliers' homecourt had proven deadly to Toronto in Games 1 and 2: a 50-point deficit combined.

The Raptors are now a loss away from ending the deepest playoff run in franchise history.

Casey has predicted a different game on their return trip to Cleveland, but it was evident virtually from the opening whistle that they were in for a long night.

"We knew they were going to come out like a freight train and they did, and we didn't meet that level of physicality on either end of the floor," Casey said.

Instead, they laid down on the tracks. In a noisy Quicken Loans Arena awash in wine and gold, the Raptors looked completely discombobulated. They were terrible in virtually every category, a dog's breakfast of poor decisions, terrible shooting, and head-slapping turnovers. Their defensive effort, against a Cavs team that opened the post-season 10-0, was half-hearted.

"We just didn't get in a rhythm," DeRozan said. "It was kind of stagnant. We had (19) turnovers, that's (19) opportunities that we could have had to at least run something. . . but we turned it away."

They'd dug themselves an 18-point deficit by late in the first quarter, and when Love drained a three-pointer late in the second, the Cavs were up by a whopping 34 points. Cleveland's 65-34 lead at the break was the biggest halftime gap in conference finals history.

When it seemingly couldn't get worse, it did. Frustration mounted. The Raptors looked like they wanted to be anywhere else. And by the end of the third, the score was a shocking 100-60.

Both teams subbed out their starters for a fourth quarter played after hundreds of fans had already departed the building. According to ESPN Stats, it was the fifth largest margin of victory in conference finals history.

Lowry and DeRozan shot just 7-for-20 between them against a smothering Cavaliers defence, and DeRozan was left lamenting his lack of activity.

"I only took eight shots, and a couple of shots came late in the game when we were down," DeRozan said. "I didn't come out aggressive like I wanted to. . . just got to understand no matter how they play, just got out there an be aggressive.

"Just eight shots throughout the whole game — that's not me."

Cavs coach Tyronn Lue had blamed their two losses in Toronto on poor shooting, and his team proved him right. The Cavs shot 57 per cent on the night. Love, who'd made just five of 23 shots in Games 3 and 4, topped Cleveland with 25 points on 8-for-10 shooting.

The Cavs grabbed 48 rebounds to Toronto's 27 — just one more than Bismack Biyombo had, on his own, in Game 3. Biyombo had just four rebounds after grabbing 40 the past two games.

The Raptors coughed up 30 points on 19 turnovers.

The series returns to the Air Canada Centre for Game 6 on Friday. A victory, however, would send them back into Cleveland for a do-or-die Game 7, where the noise reached ear-splitting levels Wednesday night in a crowd that included Montreal Canadiens star P.K. Subban and Browns defensive back Joe Haden.

While the Raptors won the regular-season series against Cleveland, all their victories came at home. They've now lost all four trips across the border this season.

Asked why the Cavs are so lethal at home, Lowry shrugged.

"I dunno," he said. "They play extremely well here. Tonight, Kevin Love got it going early, Kyrie got it going early. LeBron did what he usually does. We've got to take one of them out of the game.

"They play very well here, they've protected home all year."

Shots of Canadians Drake, Justin Bieber and Nickelback flashed on the Jumbotron, encouraging fans to boo. Late in the game, the camera focused on a downcast Raptors fan folding his "We The North" flag.

DeRozan's four points were the most by a Raptor in a first quarter that saw Toronto trail by just four points before the Cavs closed the quarter on a 17-3 run to end the frame up 37-19.

Lowry's six points topped Toronto in the second quarter, but they were barely noticeable in a quarter the Cavaliers outscored their visitors 28-15.