With just seven games left in the regular season, that lead has nearly evaporated.
Dallas tries to maintain its advantage in the Midwest, and for the top spot in the Western Conference when it hosts the Orlando Magic.
The Mavs’ once-large lead is down to one-half game over the surging Spurs. The runner-up will fall to the third seed in the playoffs because the Pacific Division champ, likely Sacramento, gets the second seed.
Dallas fell to 2-2 in its last four games, losing 100-89 at home on Thursday to the Los Angeles Lakers. The Mavs have dropped 43 of 48 against the Lakers since 1991.
“It’s slipping away,” said Mavs guard Steve Nash, who led Dallas with 26 points. “But we’re still on top.”
Dallas plays four of its last seven games on the road, including a matchup with the Lakers on Tuesday and a season-ending contest in San Antonio.
“Every game from here on out is a tough game for us, fighting for the division,” Dallas center Raef LaFrentz said. “San Antonio is right there with us and we just have to go out and do better.”
Orlando’s attempt to clinch a playoff berth took a hit this week with consecutive losses to Philadelphia and San Antonio.
The Magic are in seventh place in the Eastern Conference, and hold a five-game lead over ninth-place Washington with seven games remaining for each team.
Tracy McGrady left Tuesday’s 118-105 loss to the Spurs with just under six minutes remaining because of a strain in his side, but he still led all scorers with 30. He was coming off a 39-point performance in 118-113 overtime loss to Philadelphia on Monday.
“Something twisted in my side and it’s really, really sore right now,” McGrady said. “It’s nothing related to my back. We’re going to get treatment.”
He received treatment consisting of ice, heat and muscle stimulation Wednesday and will rest until Saturday.
STANDINGS: Magic - 4th place, 7 1/2 GB, Atlantic Division. Mavericks - 1st place, Midwest Division.
TEAM LEADERS: Magic - McGrady, 32.4 ppg, 6.6 rpg and 5.6 apg. Mavericks - Nowitzki, 24.6 ppg and 10.0 rpg; Nash, 7.2 apg.
SEASON SERIES: Magic, 1-0.
LAST MEETING: Feb. 25; Magic, 98-93. At Orlando, Fla., Gooden and Giricek scored 20 points apiece and combined for 18 rebounds as the Magic won their season high-tying fourth straight.
ROAD/HOME RECORDS: Magic - 15-21 on the road; Mavericks - 30-8 at home.
INJURIES: Magic - F McGrady (side); F-C Pat Burke (knee); F Grant Hill (ankle). Mavericks - G-F Michael Finley (hamstring); G-F Antoine Rigaudeau (back); F Walt Williams (hamstring).