The Heat are the last unbeaten team in the Eastern Conference.
Chris Bosh scored 21 points and grabbed 11 rebounds, Dwyane Wade added 19 points and Miami beat Toronto 107-102 on Sunday night, the 16th straight win for the Heat over the Raptors.
"The guys, they see how our team will have to play to be successful," Heat coach Erik Spoelstra said.
Wade also finished with 11 rebounds and seven assists for the Heat (3-0). Luol Deng scored 18 points, Shawne Williams added 16 and Mario Chalmers finished with 12 for Miami.
DeMar DeRozan scored 30 points for Toronto (2-1), which hasn't beaten Miami since Jan. 27, 2010.
"They executed well, especially down the stretch," DeRozan said. "We've got to understand when we play against a good team they're going to play well down the stretch."
It's hard to see why DeRozan lauded Miami's late execution. The Heat shot 4-for-17 in the fourth quarter and missed eight free throws in the final 12 minutes.
And they won.
"This is all going to help us later," Wade said.
Kyle Lowry added 22, including a layup that got the Raptors within four with 21 seconds left. Jonas Valanciunas scored 14 and Greivis Vasquez finished with 12 for Toronto, which was outrebounded 43-28.
"I guess it's just effort," Bosh said. "We know a lot of people aren't expecting us to do much on the boards."
Miami led by as many as 16 late in the third quarter before the Raptors came roaring back, starting with a 6-0 run to close the third and get within 10. Toronto got within six twice midway through the fourth, before Shawne Williams made a pair of big plays for Miami.
He tipped in a missed 3-point try by Mario Chalmers for an eight-point lead and after DeRozan's 3-pointer with 5:23 left got Toronto within five, he answered with a 3 of his own from the left corner to restore Miami's cushion.
Lowry had a chance to get Toronto within five again when he was fouled on a 3-pointer with about 2 minutes left, but missed two of the three tries. The Raptors missed 15 free throws on the night, after missing a total of 16 in their first two games.
"At the defensive end, it's from start to finish," Raptors coach Dwane Casey said. "You don't just guard for 23 seconds. You guard for 24 and then come up with the rebound. We're not doing that right now."
Raptors: Drake, the team's most recognizable fan, was courtside. ... The Raptors shot 39 free throws and now have a 120-79 edge over opponents in that department so far in this young season. ... Patrick Patterson got the start at forward in place of Amir Johnson, who was out with a sore left ankle.
Heat: F Josh McRoberts had to leave the game in the fourth quarter — not because of injury, but because he tore off his jersey. He was quickly issued a replacement. ... .Miami was without F Chris Andersen (sore ribs) and F Udonis Haslem (sore quadriceps). ... Miami used 11 players in the first half and each scored. ... Wade played in both ends of the back-to-back, something he did only three times last season.
Wade was 4 for 4 in the first quarter, with four rebounds and three assists. It was just the second time in his career that he made at least four shots without a miss in a quarter, along with having at least that many rebounds and assists. He had a 6-for-6, four-rebound, three-assist third quarter on Jan. 8, 2006 against Portland.
Miami fans enjoyed a perfect weekend. The Heat went 2-0, while the Miami Dolphins, Florida Panthers and Miami Hurricanes football team all went 1-0. According to STATS, it's the fourth time those teams posted a win on the same weekend and the first time they went a combined 5-0 over a Saturday and Sunday.
Raptors: Toronto hosts Oklahoma City on Tuesday.
Heat: Miami hosts Houston on Tuesday.