Boris Diaw had 14 points for the Spurs (58-16), who bettered their previous record streak of 17 games set in February and March 1996.
Paul George scored 16 points for the Pacers, who have lost six of seven and their once seemingly safe three-game lead over Miami for the Eastern Conference's top seed.
Indiana (52-23), which had maintained the best record in the conference since opening night, finished March with an 8-9 record, and in a virtual tie with the Heat in the battle for home-court advantage throughout the East playoffs.
at Miami 93, Toronto 83: LeBron James scored 32 points, and the Heat won again without Dwyane Wade and Ray Allen to take over the top spot in the East by percentage points ahead of Indiana. It's the first time all season that Miami has been alone atop the East.
at Atlanta 103, Philadelphia 95: The Hawks, clinging to the final East playoff spot, ended a six-game losing streak and won for only the seventh time in 27 games to stay a game ahead of New York. The 76ers were coming off a victory over Detroit that ended an NBA-record-tying 26-game losing streak.
Memphis 94, at Denver 92: Zach Randolph had 20 points and 11 rebounds, and the Grizzlies moved into a three-way tie with Dallas and Phoenix for seventh in the West.
at Charlotte 100, Washington 94: Kemba Walker had 21 points and 10 assists, and the Bobcats rallied from an 11-point fourth-quarter deficit to prevent the Wizards from clinching their first playoff berth since 2008.
at Detroit 116, Milwaukee 111: The Pistons used a 12-0 fourth-quarter run to subdue the Bucks.
Sacramento 102, at New Orleans 97: DeMarcus Cousins' 35 points and 14 rebounds helped the Kings end a three-game losing streak.