DALLAS(AP) Dirk Nowitzki is nearly 10 points below his season scoring average in the playoffs - and the Dallas Mavericks are still on the verge of easily advancing.

"People may say Dirk's not scoring enough, but Dirk is playing the game the right way. Playing patient, not taking any bad shots,'' Dallas guard Jason Kidd said. "I don't think he has to score 30 for us to try to win. You can see that in this series.''

Or even 20.

The Mavericks lead San Antonio 3-1 in their first-round Western Conference series, and can advance with a victory Tuesday night, even though Nowitzki has scored 20 points only once since ending the regular season with an NBA-best streak of 25 consecutive 20-point games.

"Our focus is obviously to limit Dirk and Jason Terry, and overall we're doing a good job on that,'' Tony Parker said. "Then the other guys are hurting us. ... They have a lot more weapons.''

That was all too evident in the pivotal Game 4, when Parker scored 43 and Tim Duncan came back from his worst playoff game ever with 25 points and 10 rebounds. And that still wasn't enough for the Spurs.

Even while shooting a paltry 38 percent and getting only 22 combined points from Nowitzki and Terry, one of the NBA's highest-scoring duos, the sixth-seeded Mavs took firm control of the series with a 99-90 victory Saturday.

Nowitzki made a 19-footer on Dallas' first shot of the game, then didn't shoot again until 2 1/2 minutes into the second quarter. The perennial All-Star and 2007 league MVP finished with 12 points, the last on a driving layup with 40 seconds left that helped thwart a late Spurs rally, and 13 rebounds.

"Dirk, with his last play, put it away,'' Duncan said.

Josh Howard scored 28 points, 14 in the third quarter when Dallas erased for good a Parker-infused halftime deficit. Kidd added 17 points with three 3-pointers, while Erick Dampier scored 10. J.J. Barea, in his second playoff start, and Antoine Wright each had nine points.

"Josh has given us what we've been missing,'' Nowitzki said. "When they double-team Jet and myself, other guys are stepping up.''

Terry, usually an instant-offense player who was presented the NBA's sixth man award Friday, scored 10 points. But he was only 3-of-17 shooting, missing his last 13 shots.

"We played great defense on Terry, we limited Nowitzki, but Howard had a great game and their role players hit shots,'' the Spurs' Roger Mason said.

Nowitzki is scoring 16.3 points a game in the series, down from 25.9 in the regular season. Only twice in the past eight years did the 7-foot German's scoring average decrease in the postseason.

The Spurs are in their 12th consecutive playoffs, the NBA's longest active streak and the only one longer than Dallas' nine in a row. They will try to avoid their earliest elimination since 2000.

"We're going to go home and try to win that one, and come back here and do the same,'' said Duncan, the 12th-year player and four-time NBA champion who missed the 2000 playoffs because of a knee injury. "If we can get this next game, we'll come back in here and put a little pressure on them.''

The Spurs have never lost in a best-of-seven opening series, or in the first round when Duncan played.

Dallas hasn't advanced in the playoffs since 2006, when the Mavericks made it to the NBA finals and took a 2-0 series lead before losing four consecutive games against Miami.

The Mavericks also had a 3-1 series lead over San Antonio that postseason and needed overtime in Game 7 of the second-round series to survive and advance.

"They are by no means out of this series,'' said Mavericks coach Rick Carlisle, relaying a message that his team already knows.

"They're going to throw every thing at us,'' Nowitzki said. "There are no guarantees. They're a championship team. They'll have a different motor.''

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