(SportsNetwork.com) - The Oklahoma City Thunder continue their march toward the postseason, but it'll get very difficult on Wednesday when they travel to the AT&T Center to face the defending world champion San Antonio Spurs.

OKC has won four straight and is three games clear of the Phoenix Suns for the eighth seed in the Western Conference. The New Orleans Pelicans are 3 1/2 behind the Thunder.

San Antonio is right in the thick of things in the fluid Western Conference. They are tied for sixth with the Dallas Mavericks, a half-game behind the Portland Trail Blazers for fifth and 1 1/2 behind the Los Angeles Clippers for fourth.

The Thunder haven't lost since March 16 in Dallas. Despite the streak, OKC has dropped two in a row on the road and it will visit Phoenix and Utah on this trek.

On Tuesday, the Thunder swept a four-game homestand thanks to a 127-117 beating of the Los Angeles Lakers.

Russell Westbrook, Enes Kanter and Steven Adams all posted double-doubles in OKC's victory.

Westbrook led the way with his 15th double-double in his last 17 games, finishing with 27 points and 11 assists in just under 30 minutes. Kanter now has 10 double-doubles in 15 games since joining OKC after putting up 25 points and 16 rebounds, and Adams added 16 points and 10 rebounds in the win.

"We did a good job staying in attack mode and finishing in the paint," said Westbrook.

Dion Waiters had 23 points and Mitch McGary pulled down 10 rebounds off the bench for the Thunder.

Kanter set the tone for Oklahoma City, recording 15 and 10 in the first quarter. The Thunder outrebounded LA by 10 in the first and led 37-27. The Lakers never got closer than seven after that.

The Spurs split a difficult two-game road trip with a victory in Atlanta on Sunday and a loss in Dallas Tuesday night to the Mavericks, 101-94.

Kawhi Leonard paced the Spurs with 19 points while Danny Green scored 17 for the Spurs, who had won three in a row and 10 of 12 coming in.

San Antonio couldn't contain Dallas' Monta Ellis on Tuesday. He scored 38 points on 16-for-27 shooting.

"We started out well, but after that it was the Mr. Ellis show," said Spurs coach Gregg Popovich. "We didn't contain him and he went off. That was really the ball game."

San Antonio raced out to a 14-point lead late in the opening frame, only to see the Mavs pull within three, 46-43, by intermission.

An 8-0 Dallas run early in the third quarter, followed by a 10-0 spurt late in the frame turned the tide for good. Devin Harris scored five points during the latter surge, and his bucket inside the final minute gave Dallas a 76-66 lead entering the fourth.

Dirk Nowitzki made a 3-pointer early in the final quarter during a string of seven straight Dallas points, stretching the difference to 17, and with Tim Duncan and Tony Parker resting on the bench the entire fourth frame, the Spurs did not have enough firepower to mount a comeback.

The Spurs face a challenging homestand, starting Wednesday. They'll get the Mavs in a rematch on Friday, then host the Memphis Grizzlies on Sunday evening.

The Thunder beat the Spurs by eight in the Alamo City on Christmas and the two will meet at Chesapeake Energy Arena on April 7.