Russell Westbrook's heart is something "you can't go to the supermarket and buy", Houston Rockets coach Mike D'Antoni said after their overtime victory over the Boston Celtics.

Westbrook scored 41 points on Saturday as the Rockets edged a thrilling game with the Celtics 111-110 at TD Garden.

The win moved the Rockets to 39-20 for the season, with Houston fourth in the Western Conference standings.

"You can't go to the supermarket and buy heart," D'Antoni said of Westbrook. "You know he has that. It's pretty impressive."

Celtics guard Jaylen Brown hit a buzzer-beating three-pointer to send the game to overtime.

However, he conceded the Celtics did not defend well against Westbrook, having held his fellow former MVP, James Harden, to 21 points.

"I think we guarded [Harden] well," Brown said. "I think we accepted his challenge. We just didn't do a good enough job with Westbrook.

"We had a lot of attention on James Harden and forgot about the other MVP over there. He came out and asserted himself early and took over and dominated this game."

The Rockets' decision to trade center Clint Capela in January appears to have had an instrumental impact on Westbrook.

Houston have tweaked their style of play to afford him more opportunities to attack the basket, but Westbrook was non-committal on whether those changes have put him in the best position ever to succeed.

"I don't know, man," Westbrook said. "I just try to find ways every year to be better and find ways to become a better player and team-mate.

"Obviously based on the changes we made and the way we line up, I have to find ways to constantly keep being effective and help my team win games and that's what I try to do.

"Right now, I think I'm moving in the right direction. I've just got to stay locked in on what I'm doing and my craft and keep doing what I've been doing since I've been in the league, and that's going out and competing every night."