One game after clinching a playoff berth, Houston delayed host Washington's bid to secure its own spot Sunday, winning, 99-91, behind James Harden's 24 points.
Washington's John Wall led all scorers with 25 points.
Houston's Dwight Howard had 11 points and 10 rebounds in 19 minutes in his third game back from a right-knee injury.
Harden only made 7 of 20 shots but went 9 for 10 at the foul line. He added six assists and one into-the-stands block of Bradley Beal's three-point try with 25 seconds left.
Trevor Ariza, who left Washington as a free agent after last season, contributed 13 points, eight rebounds and active defense for Houston, which led by as many as 16 in the first half.
Thunder 109, Suns 97 - Russell Westbrook had 33 points, nine rebounds and seven assists, and Oklahoma City rallied from 20 points down to beat host Phoenix. D.J. Augustin scored 13 of his 19 points in the fourth quarter for the Thunder, who snapped a four-game road skid. Markieff Morris scored 24 points for the Suns, who dropped four games behind Oklahoma City.
Nets 107, Lakers 99 - Brook Lopez had 30 points and 11 rebounds, and host Brooklyn kept up its playoff push by beating Los Angeles for its third straight victory. Joe Johnson added 18 points, eight rebounds and seven assists for the Nets. Reserve Jordan Hill had 22 points and 16 rebounds for the Lakers.
Pelicans 110, Timberwolves 88 - Anthony Davis had 28 points and nine rebounds, and New Orleans defeated visiting Minnesota. Omer Asik added 15 points for the Pelicans. Andrew Wiggins had 20 points and Zach LaVine 17 for the Timberwolves.
Clippers 119, Celtics 106 - J.J. Redick scored 27 points, Chris Paul had 21 points and 10 assists, and Los Angeles beat host Boston for its seventh consecutive win. Blake Griffin added 21 points and nine rebounds for the Clippers. Isaiah Thomas led the Celtics with 19 points.
Heat 109, Pistons 102 - Dwyane Wade scored 40 points one day after having fluid removed from his balky left knee, Udonis Haslem set season highs with 18 points and 13 rebounds, and undermanned Miami beat visiting Detroit. Andre Drummond had 32 points and 14 rebounds for the Pistons.
Spurs 103, Grizzlies 89 - Kawhi Leonard had 25 points and 10 rebounds and San Antonio cruised past visiting Memphis. The Spurs shot 51 percent from the field and had 25 assists in handing the Grizzlies their third straight loss. Zach Randolph had 20 points and 13 rebounds and Jeff Green had 19 for Memphis.
Pacers 104, Mavericks 99 - C.J. Miles scored 28 points and made a key three-pointer with a minute left to help host Indiana get past Dallas. Chandler Parsons led Dallas with 27 points.