MEMPHIS, Tenn. -- Oklahoma City's Russell Westbrook owned the third quarter, but Memphis backup point guard Mario Chalmers owned the fourth.

In only his third game with the Grizzlies, Chalmers - who heard chants of "M-V-P, M-V-P" from fans at FedExForum - set his career high for points off the bench with 29 as Memphis defeated the Thunder 122-114 on Monday.

"Imagine when he knows the plays," said center Marc Gasol, who had 17 points with six assists and six rebounds.

Chalmers, recently acquired in a trade with Miami, has been learning on the fly. So much so, that he said his postgame plans included studying the Memphis playbook on his IPad.

As for those MVP chants?

"I don't want to talk about that," Chalmers said with a smile.

The chants came from fans who used to boo him because he hit a big shot for Kansas in its 2008 NCAA title game victory over the University of Memphis.

"It gave me more motivation to prove I belong here," he said.

So far, so good.

Chalmers scored 16 points in the fourth quarter, and knocked down two of his four 3-pointers in the period.

The Grizzlies (6-6) won their third straight as starting point guard Mike Conley scored 22 points with nine assists and, like Chalmers, hit four shots from long distance.

Westbrook had a double-double with 40 points and 14 assists, going 13 for 19 from the field and 5 for 8 from 3-point range.

But it was the Grizzlies' continued hot shooting from 3-point range, making 12 of 17.

"It's something we gotta live with," Westbrook said of the Grizzlies' unexpected long range shooting (they entered the game ranked 28th in the NBA in 3-point field goal percentage at 29.1 percent). "This team lives in the paint and tonight some guys made shots they don't usually make."

Said Oklahoma City coach Billy Donovan: "I've always been a big believer that whenever a 3-point shot goes up, it's dangerous."

Westbrook scored 17 of the Thunder's 28 points in the third quarter and from the 4:53 mark in the third to the 2:17 mark, he scored all 13 of Oklahoma City's points.

The third quarter ended with Westbrook raising up as if to take a 3-pointer before the buzzer, only for him to flip a pass to guard Cameron Payne, who hit a 3 for an 80-79 Thunder lead going into the final frame.

"We did a good job of sticking together," Westbrook said, noting that they rallied again in the fourth quarter.

Memphis took control early in the fourth period hiked the lead to 106-95 with 3:40 remaining. Westbrook hit a 3-pointer with 1:02 left to cut the lead to three at 111-108.

"We gave ourselves a chance," Donovan said.

But they never drew closer.

The Thunder (6-5) shot 50.6 percent from the floor while Memphis shot 44. The Grizzlies were productive at the free-throw line, going 36-for-39 with Chalmers 13 for 15.

Forward Zach Randolph contributed a double-double with 12 points and 10 rebounds while Jeff Green scored 20.

The Thunder got 18 points and nine rebounds from forward Serge Ibaka and forward Enes Kanter chipped in 16 points.

Meanwhile, Chalmers is averaging 18.7 points through his first three games and just as important taking some of the load off Conley while providing better spacing for the offense and more length and athleticism on defense.

"He's feeling a lot of confidence, and he's feeling a lot of love," Grizzlies coach Dave Joerger said. "So I told him, 'Welcome to Memphis.'"

NOTES: Thunder F Kevin Durant missed his third straight game with a left hamstring strain. Coach Billy Donovan didn't offer a time frame for his return: "He'll probably go back to the doctor." ... G Andre Roberson also was out Monday with the flu; F Kyle Singler started in his place. ... The Grizzlies are coming off their best offensive performance of the season Sunday in Minnesota, where they beat the Timberwolves 114-106. They entered that game with the NBA's worst shooting percentage (40.1), but shot a season-high 56.3 percent by making 40 of 71 from the field. They also went 9 of 17 from 3-point range for 52.9 percent. ... Oklahoma City PG Russell Westbrook entered Monday's game first in the league in assists (10.3), sixth in steals (2.20) and seventh in scoring (25.4). ... When scoring at least 100 points, Memphis is an NBA-best 38-3 (.927) since the start of last season.