THUNDER 109, BUCKS 89: Russell Westbrook led all scorers with 26 points as Oklahoma City staked its claim to the top spot in the Western Conference while denting Milwaukee's playoff hopes.

Westbrook struck for 10 points in a dominant first quarter and the Thunder (42-15) cruised from there to move one game ahead of San Antonio for first place in the conference after the Spurs lost 91-84 at Utah on Monday.

Kevin Durant added 19 points and James Harden chipped in with 16 in a reserve role. Thabo Sefolosha contributed 14 points and seven steals.

Ersan Ilyasova had 18 points to pace the Bucks (28-29), who saw their four-game winning strek halted. The loss was a damaging one for the Bucks, who fell 1 1/2 games back of the idle New York Knicks and Philadelphia 76ers for the eighth and final playoff spot in the East.

The Thunder opened up an 18-point lead after the opening quarter, and the game remained one-sided until Milwaukee staged a rally in the closing moments of the first half. Brandon Jennings and Drew Gooden kicked off the spurt with 3-pointers and Jennings capped it with a driving layup as the Bucks closed to within 11.

Westbrook answered with a 3-pointer at the buzzer to send the Thunder into the break with a 61-47 edge.

Oklahoma City gradually stretched out the lead throughout the third quarter and put the game away midway through the fourth, with Derek Fisher knocking down consecutive shots to make it 100-77.

GAME NOTEBOOK: Bucks forward Larry Sanders was ejected in the fourth quarter after throwing an elbow at Thunder forward Nick Collison. Sanders finished with two points, three rebounds, a steal and a block in 14 minutes. ... Each of Milwaukee's four victories during the streak came against teams with losing records. ... Oklahoma City hit from everywhere, shooting 48.1 percent from the floor, 40 percent from 3-point range and 92 percent from the free throw line. ... The Bucks, who entered the night second in the NBA in assists at 23.6 per game, had 26 against the Thunder.