Atlanta forced overtime with a pair of late 3-pointers. Marvin Williams made one with 33.5 seconds left in the fourth quarter to cut the lead to three, then Johnson stole a pass inside and brought the ball up the court. Johnson looked like as if might have hurt himself, but he kept the ball and sank a tough 3-pointer over Rodney Stuckey to tie it.
The Hawks started the extra session with a 12-2 run, including 3-pointers by Williams and Josh Smith.
Greg Monroe scored 22 points for the Pistons.
Johnson was 1 of 9 from the field in the first half, but he recovered in a big way, surpassing 14,000 points for his career and continuing a strong stretch for him since the Hawks lost Al Horford earlier this month to a torn pectoral muscle.
The Hawks are now 10-1 when Johnson scores at least 20 points.
Atlanta rallied from an 11-point halftime deficit to tie it in the fourth quarter, but Jason Maxiell’s three-point play put the Pistons ahead 73-70 and started what looked like a decisive 8-0 run.
But the Pistons couldn’t hold on, starting a stretch of seven games in nine days on a sour note. Detroit had a chance to win it even after Johnson’s big 3-pointer in the final seconds of the fourth, but Brandon Knight’s last-second shot wasn’t close.