Tyler Hansbrough scored 21 points for Indiana, which squandered a 16-point second half lead before a dramatic, back-and-forth final sequence.
With 11.1 seconds remaining, Austin Daye's 17-footer gave the Pistons their first lead since the first quarter, but on the ensuing possession, Danny Granger drew a double-team and found Rush for a dunk in traffic in the lane.
A turnover on the ensuing possession secured the victory for Indiana, which won for the ninth time in 12 games since interim coach Frank Vogel took over for Jim O'Brien in late January.
Greg Monroe scored 27 points for the Pistons, who lost for a 10th time in 14 games.
Granger scored 17 in the second half for Indiana, and had 10 during the fourth quarter.
Tracy McGrady scored eight points in the third quarter, and he and Monroe helped the Pistons turn the game's momentum. Detroit kept it close after pulling to within two early in the period, but couldn't move into the lead until Daye's late jump shot.
The victory allowed Indiana to remain one of the league's hottest teams. The Pacers, who won seven of 10 games before the All-Star break, have won their two games coming out of the break.
Rodney Stuckey had 21 points for Detroit, which stayed close in the first quarter before Hansbrough helped the Pacers pull away with an energetic second quarter.
Hansbrough, who missed much of last season has continued to improved in his second season, scored 10 points in the period for Indiana, and he was a dominant factor offensive rebounding.
He shot 5 of 9 in the period, but had five offensive rebounds, and six of his second-quarter points came on follow shots.
Point guard Darren Collison had 11 points and six assists, and forward Josh McRoberts and rookie Paul George added 10 points each for Indiana, which shot 44.2 percent from the field despite making just 3 of 17 3-point field goals.
McGrady had 16 points and and Ben Wallace had 10 rebounds for Detroit, which shot 48.8 percent and 50.0 percent from 3-point range, but lost for a 10th time in 14 games.