TORONTO -- Stephen Curry's otherwise sparkling stat line had one ugly entry: six turnovers, four of them in a costly fourth quarter.
Curry scored 34 points, topping the 30-point plateau for a career-best 15th time, and David Lee had 20 points and 11 rebounds as the Warriors lost for just the second time in seven games since the All-Star break.
Curry was at fault on four of Golden State's six turnovers in the fourth, leading to nine Toronto points.
''We just lost our composure on the offensive end a little bit,'' Curry said. ''Obviously, we put ourselves behind the 8-ball.''
Golden State coach Mark Jackson called it a ''disappointing loss,'' and singled out Curry's giveaways as an area of concern.
''Steph is good enough, no matter what defense he's seeing, to not leave it with six turnovers,'' Jackson said. ''He knows he's got to be better.''
Jackson said some of the turnovers happened when the Warriors ''tried to do too much.''
''Instead of taking the shots that were available, we tried to be a little too unselfish and over-pass and found ourselves in trouble because of it,'' Jackson said.
Before the game, Toronto coach Dwane Casey called Curry a ''one-man wrecking crew.'' After Curry scored 29 points through three quarters, it appeared the Raptors were headed toward another defeat to the All-Star guard.
Instead, Curry's handle deserted him in the fourth, wrecking Golden State's lead.
''The fact they came one after the other made it tough,'' Curry said of his untimely miscues. ''It's very frustrating.''
Toronto's only previous victory over Golden State since Curry was drafted was an 83-75 home win on March 4, 2012, a victory that came while the guard was sidelined by a strained tendon in his foot.
Klay Thompson scored 12 points and Harrison Barnes had 11 for the Warriors, who played without Jermaine O'Neal. The veteran big man was unable to travel to Toronto because of a misplaced passport, and will rejoin the team for Tuesday's game at Indiana.
Back-to-back baskets by Barnes and Draymond Green gave the Warriors an 84-78 lead with 9:30 remaining, but Toronto took the lead with a 14-2 run over the next 3½ minutes, including 3-pointers from DeRozan and Patterson.
''Down the stretch we buckled up and took them out,'' Casey said.
DeRozan scored seven points during the surge, and a running dunk by Patterson caused Golden State to call timeout trailing 92-86 midway through the final quarter.
''DeRozan hit a bunch of tough, contested ones,'' Lee said. ''He had a big night.''
Golden State's Andrew Bogut briefly quieted the crowd of 18,658 with a dunk off a pretty feed from Lee, but Patterson answered with a corner 3.
After a jump shot by Andre Iguodala, Curry scored his first points of the fourth on a layup. DeRozan answered with a layup at the other end, but Thompson hit a 3 with 3:35 left to bring the Warriors within 97-95.
It stayed that way until a dunk by Amir Johnson a minute later. Curry turned the ball over on the next possession, leading to a jump shot for Toronto's John Salmons, putting the Raptors up 101-95 with 1:55 remaining. Curry hit one more 3, but Johnson sealed victory for Toronto by making one of two from the line.
''That's a good team, a well-coached team enjoying a very good year, but a bad loss for us,'' Jackson said.
Curry and Lee each had 10 points as the Warriors led 28-25 after one quarter.
Curry scored 14 points in the third, shooting 5 of 8 as Golden State took a 78-75 edge into the final quarter.
Golden State has lost its first game in the month of March in each of the past six seasons. ... DeRozan went 11 for 12 at the free throw line. ... Bogut finished with 10 rebounds. ... Golden State overcame a 27-point deficit to beat Toronto 112-103 in their previous meeting, Dec. 3, 2013. ... Toronto's next game is Friday, March 7 at home to Sacramento. ... Toronto Maple Leafs player Joffrey Lupul and former Olympic 100m champion Donovan Bailey attended the game.