The Spurs beat the Mavericks for the ninth straight time in the regular season, a streak that has lasted more than two years.
Tim Duncan had 20 points and 15 rebounds after leaving briefly in the first quarter because of a hyperextended right knee. Kawhi Leonard added 16 points, a career-high 16 rebounds and five assists.
Monta Ellis led Dallas with 24 points and Dirk Nowitzki had 19.
The Spurs are just a win or an Oklahoma City loss away from securing the top seed in the West.
The Mavericks (48-32) are in a three-team scrum with Phoenix and Memphis their opponents in the final two games for the final two playoff spots a year after missing the postseason for the first time since 2000. Dallas is in a virtual tie with the Suns (47-31) and a game ahead of the Grizzlies (46-32).
NUGGETS 100, WARRIORS 99
OAKLAND, Calif. • Kenneth Faried made a turnaround hook shot over Draymond Green with a half-second remaining, and the Denver Nuggets made Golden State wait at least one more game to secure a playoff berth with a stunning win over the Warriors.
Stephen Curry's floater over Faried put the Warriors up 99-98 with 4.7 seconds to play, sending the announced sellout crowd of 19,596 roaring to their feet. Faried quieted fans moments later, backing down Green for the winning shot.
Curry's quick 30-footer rimmed off as time expired.
Timofey Mozgov tied a career high of 23 points and set a career best with 29 rebounds, and Faried finished with 18 points and 17 boards to rally the Nuggets from 20 points down in the first half. Denver, which had lost six straight on the road, won both games at Golden State this season.