"If you want to win, you got to play defense," Leonard said. "That is every game in the NBA."
Leonard and Pascal Siakam each scored 30 points, with Siakam setting a career high, and the Raptors beat the Milwaukee Bucks 123-116 on Saturday night in a matchup of the top two teams in the NBA standings.
Leonard also matched his season high with five steals.
Serge Ibaka added 25 points and nine rebounds, Fred VanVleet had a season-high tying 21 points and Danny Green 12 points and nine rebounds for Toronto which snapped a three-game losing streak to Milwaukee.
Toronto improved to 29-12, and Milwaukee dropped to 27-11.
Milwaukee led in the first quarter, but saw the margin shrink to one at the half as Toronto started making shots and playing defense.
"I thought that we kind of took some air out of them a little bit there," VanVleet said. "That was a huge way to close the half. We closed it (the second) with a 7-0 run and came out in the third quarter with another run. I thought that we were in control for the rest of the way."
The Bucks clung to a 57-56 lead at the half, but the Raptors had already turned the game in their favor.
"We kind of let up the second quarter going into the half," the Bucks Eric Bledsoe said. "They cut it to one and we kind of let up then. We never could get our rhythm back."
Toronto opened the third with a 26-12 run, capped by Siakam's turnaround bank hook for a 63-57 lead at the 10:05 mark.
"What helped us was the beginning of that third quarter," Leonard said. "We came out in the first two minutes playing well, getting stops, getting some open looks. We kept moving from there."
Antetokounmpo tried to rally the Bucks in the fourth when he scored eight points on a pair of 3s and a layup during a 14-4 run. His three-pointer gave Milwaukee a 96-95 lead with 8:12 to play, but the Raptors answered with a 15-2 surge capped by Siakam's wide-open 3 from the corner for a 110-98 lead with 5:14 to play.
Milwaukee was coming off a 144-112 victory over Atlanta on Friday night.
Raptors: C Jonas Valanciunas (left thumb dislocation) missed his 11th consecutive game. G Kyle Lowry (lower back pain) missed his sixth straight game. ... The last time Lowry and Leonard played together was Dec. 9 against Milwaukee.
Leanard has seven games of 30 or more points on 50.0 percent shooting or better.
The Bucks lead the season series 2-1 with one more game remaining in Toronto on Jan. 31.
Toronto had a day to rest following a 125-107 loss to the Spurs on Thursday night in Leonard's return to San Antonio.
"Tonight, executed everything in our game plan defensively and one game (Spurs) we didn't execute any of it," Toronto's head coach Nick Nurse said. "Also, (we) played with some juice and some physicality. That is the way we need to play if you want to be a serious contender."
Raptors: Host Indiana on Sunday night.
Bucks: Host Utah on Monday night.
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