Jrue Holiday had 27 points and 12 assists and Spencer Hawes had 18 points, 16 rebounds, eight assists and seven blocks on Saturday night as the host Philadelphia 76ers used a fourth-quarter surge to defeat the Indiana Pacers, 98-91.
It was the fourth loss in six games for the Pacers (40-26), who likely will clinch a NBA playoff berth this week and lead the Central Division. But their recent slide has left them just a half-game in front of the New York Knicks, who are third in the East.
In three of the losses, Indiana's offence has disappeared for extended stretches of the fourth quarter.
The Pacers were scoreless for the last 4:35 of a home loss to Boston on March 6 and went cold down the stretch of Friday's home loss to the Los Angeles Lakers.
It happened again on Saturday against the Sixers, who began the final period with a 13-2 run capped by two baskets from Evan Turner that turned a one-point deficit into an 84-74 lead with 8:42 to play. The Pacers missed seven straight shots and committed three turnovers during that period.
Roy Hibbert had 25 points and 10 boards for Indiana.
Meanwhile, San Antonio downed Cleveland 119-113 on the back of another dominant performance from the ageless Tim Duncan.
Duncan had 30 points, 12 rebounds and five blocks for the Spurs (51-16), who are a half-game behind Miami for the NBA's best record.
In Boston, the Celtics avenged a loss to Charlotte four days ago with a 105-88 victory in which Jason Terry scored 15 points to lead six players in double figures.
Elsewhere, the Washington Wizards routed the visiting Phoenix Suns, 127-105, the Utah Jazz beat the Memphis Grizzlies, 90-84 and the Portland Trail Blazers prevailed over the visiting Detroit Pistons, 112-101.