MEMPHIS, Tennessee The San Antonio Spurs continued an impressive end-of-season winning streak with a 113-92 rout of the Memphis Grizzlies on Saturday.

The win, on the back of Tim Duncan's 30 points and 14 rebounds, was the Spurs' seventh in a row.

It ensured they remained atop the Midwest division by half-a-game over Dallas. They can wrap up their third Midwest title in four years by winning their final two games.

However, winning the division will put the Spurs on the same side of the bracket as the Los Angeles Lakers, who swept San Antonio in the conference finals a year ago.

On Saturday against Memphis the Spurs built a 21-point lead after the first quarter and never looked back.

The 44 points in the first quarter were the most ever allowed by the Grizzlies in the opening quarter.

Malik Rose aided Duncan with 26 points and 11 rebounds for the Spurs, while rookie Pau Gasol led Memphis with 19 points.

Meanwhile in Seattle, the Dallas Mavericks showed they weren't prepared to hand the Midwest title to their rivals, with a 116-99 victory over the Seattle Supersonics.

Michael Finley scored 29 points to lead six players in double figures as the Mavericks remained just behind San Antonio for first place in the Midwest division.

The Mavericks, who blew a 20-point lead against the Houston Rockets on Thursday, did not make the same mistake again, when they opened out a 62-46 lead by halftime.

Dallas then went on a 16-2 burst three minutes into the third quarter that was capped by a jumper and free throw by finley to extend its lead to 80-54 with 6:56 left in the quarter, Reuters reported.

Seattle trailed 96-66 entering the fourth quarter and did not threaten again.

Dallas guard Nick van Exel scored 22 points while Greg Buckner (17), Raef Lafrentz (14) and Eduardo Najera 14 and 11 rebounds all contributed for the Mavs.

Gary Payton had 21 points, seven assists and six rebounds for the Sonics.