Westbrook scored 18 points, making two free throws with 7.3 seconds left to lift the Thunder to an 82-81 victory over the Milwaukee Bucks on Saturday night.
Harden did his part, too.
He made his second career start for Oklahoma City a good one, with season highs of 23 points, nine rebounds and six 3-pointers.
Durant, the NBA scoring leader, also sat out Friday's victory in Boston with a sprained left ankle. Jeff Green, who is third in scoring with 18.2 points per game, was also on the sidelines for a fourth straight game -- seventh overall -- with a sprained left ankle.
"It shows we have a lot of heart," Harden said. "Even though Kevin and Jeff are out, it had to bring our teammates that much closer together, really lock in on our defensive end because it's going to be tough. We put up two good victories."
Harden came in averaging 7.6 points but shot 6 of 13, with all of his field goals coming from 3-point range.
Thunder coach Scott Brooks said that when Harden is aggressive and quick with his decisions, he plays better.
"He knows it drives me crazy," Brooks said about Harden's tendency to set up slowly for his shot. "I've never had the luxury of a coach wanting you not to hesitate on your shot."
Westbrook scored 31 points in Oklahoma City's 89-84 victory over the Celtics in Boston on Friday.
"Winning last night in Boston and coming here, that's great that we did that," Brooks said. "All we do is just compete every night and see where it takes us. Don't get too high, don't get too down. Just stay focused on the work every day."
Brandon Jennings led the Bucks with 25 points, 13 in the fourth quarter as he tried to spark the Bucks' woeful offense.
Trailing by 13 early in the third quarter, the Bucks rallied to cut the margin to one three times in the final two minutes, the last coming on Drew Gooden's follow shot that made it 82-81 with 1.2 seconds left.
Bucks coach Scott Skiles said that the Bucks have to clean up their sloppy play at crunch time.
"At really key moments when we need to make a play, we struggle to make it and sometimes actually made a bad play, sort of an errant pass or something like that that's hurt us," he said.
Maynor scored 12 points and Westbrook added six assists as the Thunder won their fourth straight game.
Gooden had 16 points and a season-high 16 rebounds for the Bucks, who slipped three games under .500 with their third straight loss.
The Bucks came in with an NBA-worst 41.4 shooting percent and shot even worse, finishing the game at 37.7 percent. The Thunder made it closer than it might have been by shooting 37 percent and scoring their fewest points since a 92-83 loss to the Celtics on Nov. 7.
The Bucks chipped away at the Thunder's 13-point lead in third quarter and got within four on Jennings' driving layup, but Nick Collison hit a 17-foot jumper to send Oklahoma City into the fourth quarter with a 62-56 lead.
It was Durant's second game out since he missed seven straight in March 2009. ... The Thunder snapped a six-game losing streak to the Bucks at the Bradley Center, a streak that dates back to the franchise's Seattle days. ... Bucks F Carlos Delfino missed his fifth straight game with a neck sprain. No timetable has been set for his return. ... The Bucks had 42 points in the paint to Oklahoma City's 26.