"He's our closer and he has been that way for the last couple of years," Duncan said. "He steps up and makes big shots for us. That's what we ask him to do and he's delivered for us."
Manu Ginobili scored 15 points, Danny Green had 13 and Boris Diaw 11 as the Spurs won their third straight and improved their NBA-best road record to 7-1.
"We take pride in winning on the road," Ginobili said.
Parker made jump shots on consecutive possessions with less than 1 minute, 15 seconds to go in the second overtime as the Spurs held on.
"We had to work hard for this one," Parker said.
Spurs coach Gregg Popovich agreed, not that he was happy about it.
"In a lot of ways, [Toronto] played better than we did," Popovich said. "They destroyed us on the boards. For most of the meat of the game they just threw it up there, missed it and they'd go get it again. That kept them in the ballgame. We did a better job in the overtimes defensively and on the boards, and that got us over the hump."
DeMar DeRozan led Toronto with 29 points, while rookie Jonas Valanciunas had 22. Kyle Lowry scored 20 points and Ed Davis had 15 points and 14 rebounds for the Raptors, who have lost their past three games by a combined seven points.
Toronto's Andrea Bargnani had a disappointing game, scoring four points and making just two of 19 field goal attempts.
"Today was definitely a very bad night," Bargnani said. "Maybe the worst."
Raptors coach Dwane Casey dismissed suggestions that he should have benched Bargnani, the first overall pick in the 2006 draft. "I've got to go with Andrea," Casey said. "He's our guy."
In other games: *
At Denver, Andre Iguodala scored 23 points, including 3-for-4 from three-point range, and Kenneth Faried added 14 points and 12 rebounds as the Nuggets rolled over the New Orleans Hornets, 102-84.
* At New York, Carmelo Anthony scored 29 points in just 32 minutes, and the Knicks ended a two-game losing streak with a 121-100 victory over the Detroit Pistons. Steve Novak added a season-high 18 and JR Smith had 15 points and 10 rebounds for the Knicks, who improved to 5-0 at home.
* At Brooklyn, Joe Johnson scored 21 points, Brook Lopez had 15 and the Nets beat the Portland Trail Blazers, 98-85. Brooklyn has won five straight games at Barclays Center.
* At Orlando, Kevin Garnett had 24 points and 10 rebounds, Paul Pierce added 23 points and Rajon Rondo was one rebound shy of a triple double with 15 points and 16 assists as the Boston Celtics outlasted the Magic, 116-110, in overtime.