Becky Hammon struck for a season-high 37 65 victory over Los Angeles.
Tully Bevilaqua scored 11 points off the bench, while Jia Perkins tallied 10 for the Silver Stars, who will participate in the postseason for a fifth straight year.
Tina Thompson posted 18 points and DeLisha Milton-Jones added 16 with eight boards for the Sparks, who were officially eliminated from postseason contention.
San Antonio led by two after three quarters, but used a 12-0 run to provide some breathing room. Bevilaqua ended the burst on a three-pointer with four minutes remaining to give the visitors a 73-58 edge.