TORONTO -- With Chris Bosh back home on dad duty, the Miami Heat had to make do with the "Big Two."
But despite a good start for Toronto, it was business as usual for the Heat.
DeMar DeRozan had 21 points to top the Raptors (2-2), who fell apart in the fourth quarter against the two-time defending NBA champions.
"We're still a good team, we lost to a good team, we lost to the defending champs. Two-time defending champs," said Rudy Gay, who had 13 points and 10 boards. "But we still can grow, we played them pretty solid for three quarters, we've just got to learn how to finish games out."
Bosh -- the third piece of Miami's "Big Three" -- didn't make the trip for the game that came a day after his wife Adrienne gave birth to their daughter Dylan Skye.
The former Raptors all-star, who spent seven seasons in Toronto, is averaging 19.8 points and 6.8 rebounds a night. But his absence was barely noticeable -- save for the fact he wasn't there for fans to boo -- as James and Wade more than carried the load.
When they weren't scoring, they were helping each other score.
"To see it now and to where it was before, you don't see all the hours of commitment on their part to develop different parts of their game, and that specifically is: what are they doing without the basketball?" Heat coach Erik Spoelstra said on the chemistry between his two stars.
"Early on, when we put this team together, it was a challenge, they were used to having the ball so often in their hands, particularly in pivotal moments during the game, and they had to learn how to adjust, play off the ball. . . and they've both done a tremendous job, for marquee players to make that adjustment is much easier said than done."
Ray Allen had 14 points for Miami (3-2).
The Heat moved the ball with high-speed precision, totalling 31 assists to Toronto's 15.
Still, the Raptors led by as much as 11 points in the second quarter before Wade, looking as if he was toying with Toronto, scored on a turnaround jumper at the buzzer to end the third. The basket gave the Heat a 78-74 lead heading into the fourth and sucked all the life out of Toronto.
The Heat opened the fourth with a 12-0 run, and held the Raptors scoreless for more than five minutes in about as ugly a quarter as you can get.
The Raptors had nine turnovers, and Lowry's driving layup with 3:58 left in the game was Toronto's first field goal in the quarter. The game was out of reach by that point, and many of the 18,470 fans at the Air Canada Centre were already headed for the exits.
"I thought our guys battled for three-and-a-half quarters, but those turnovers in that one stretch broke our back," Raptors coach Dwane Casey said.
The Raptors' string of futility versus Miami is the team's longest active losing streak.
James reached another milestone during the game, becoming the fifth player in NBA history to score 10 points or more in 500 consecutive games, achieving the feat with a huge first-quarter dunk. The four-time NBA MVP joins Kareem Abdul-Jabbar (with streaks of 787 and 508 games), Michael Jordan (866), Karl Malone (575) and Moses Malone (526) as the only players to accomplish the feat.
"I felt good," James said. "And I'm getting there. I'm getting to where I'm going out there and feeling like I was at the end of last year. That was a great road win for us tonight."
Joel Anthony of Montreal played just nine minutes for the Heat and had two boards and zero points for the Heat.
Valanciunas had 10 points in the first quarter to give the Raptors a nine-point lead. But Allen drained a three to cap a Miami run and pull his team even at 23-23. The Raptors led 25-23 heading into the second.
A Valanciunas hook shot gave Toronto an 11-point lead with five minutes to go in the first half, but Mario Chalmers' buzzer-beating three capped an 18-5 Heat run and gave Miami a 52-50 advantage at halftime.
The Raptors and Heat meet three more times this season, including Nov. 29 at Miami.
NOTES: The Raptors are at Charlotte on Wednesday, and Indiana on Friday before returning home to host the Utah Jazz on Saturday. . . Rapper Macklemore had a courtside seat and helped chuck T-shirts into the crowd during a timeout. . . DJ Jazzy Jeff and Toronto Maple Leafs James Reimer and Phil Kessel were also seated courtside.