DALLAS -- Lately, it's getting harder to tell the Dallas Mavericks and playoff teams apart.

The Mavericks knocked off another unit destined for the postseason by rolling over the Oklahoma City Thunder 104-89 Sunday night at American Airlines Center.

Seth Curry scored 22 points two nights after Dallas beat Memphis 104-100 to open a five-game homestand. The Mavs (26-36) have won four of their last five, including wins over the Thunder and Grizzlies, two squads occupying Western Conference playoff positions.

That is where the Mavs want to be, and judging by their recent uptick, they have got a chance to get into the top eight. Dallas is only two games behind No. 8 Denver (28-34) with 20 games left in the regular season.

Oklahoma City (35-28) appears to be in good shape to get into the playoffs, but there are red flags going into the stretch run. The Thunder lost their third in a row overall and their seventh straight on the road.

"We have to be more physical," NBA leading scorer Russell Westbrook said. "We have to be a physical team every night. Come out and compete, especially on the defensive end."

Westbrook seemed to be thoroughly frustrated by the Mavs, especially by the physical defense of Wesley Matthews. Westbrook scored 29 points, 14 coming in the first period, but shot only 8 of 24 to go along with six rebounds and five assists.

"You make Westbrook work," Dirk Nowitzki said. "He's so explosive and has an incredible scoring game, so we tried to concentrate and pack the paint and obviously it helped that they didn't shoot the ball well from the outside."

Westbrook also picked up his 14th technical foul on the season and a flagrant-1 foul for shoving Harrison Barnes in the third quarter.

Curry racked up 15 in the first half and hit the 20-point plateau for the fourth consecutive game and the fifth time in the last six. He is averaging 23.3 points in his past six games.

"I have a lot of confidence right now," said Curry, who has 10 20-point games this season. "I'm trying to play with a lot of energy and have a lot of fun out there."

Nowitzki started strong and finished with 18 points and 12 rebounds for his fifth double-double this season. The future Hall of Famer needs just 20 points to become the sixth player in NBA history to reach 30,000 for a career.

Barnes added 17 points, and Nerlens Noel scored 13 and grabbed five boards off the bench.

The Mavs shot out of the gates on fire, shooting 62.8 percent in the first half to take a 60-50 lead into the break. Thunder coach Billy Donovan traced his team's problems back to defense, not missing bodies like Victor Oladipo or recent additions like Taj Gibson.

"We need to keep getting better and making improvements in that area," Donovan said. "I don't think it's anything with our new guys, or anything along those lines. I think collectively as a group we've all got to do a better job defending at a higher level.

The Thunder went ice cold to open the third quarter, with Matthews particularly getting into Westbrook. Dallas opened up a 23-point lead and cruised to its first win over Oklahoma City since the 2014-15 season.

Center Steven Adams had 19 points for the Thunder, while backup Enes Kanter scored 16 and pulled down 10 rebounds.

The Mavs reach the middle point of their homestand Tuesday against the Los Angeles Lakers.

Oklahoma City returns home for three games beginning Tuesday against the Portland Trail Blazers.

NOTES: Asked if Thunder PG Russell Westbrook is in the MVP mix, Mavs owner Mark Cuban said: "He's not." Cuban listed Houston PG James Harden and Cleveland F LeBron James as favorites. Dallas coach Rick Carlisle did say he's in awe of Westbrook's skills. ... Oklahoma City had a five-game winning streak against Dallas snapped. ... Thunder G Victor Oladipo (back spasms) remained in Oklahoma City and missed his sixth consecutive game. ... Thunder G Alex Abrines left the game after being poked in the eye in the first half and did not return. ... The Mavs recalled C A.J. Hammons and G/F Nicolas Brussino from the D-League Texas Legends. Brussino played three scoreless minutes.