"I thought we played pretty steady throughout the ball game," Hawks coach Mike Woodson said. "But coming down the stretch we just unraveled and didn't make the plays that we needed to make."
Trailing by three at the half, Atlanta used back-to-back 3s from Bibby and Evans -- along with some spotty Toronto shooting -- to help build an eight-point lead late in the third quarter. Evans added another 3 in the final minute to put the Hawks up 86-75 entering the fourth quarter.
Bosh's jumper cut it to five, but Evans hit an uncontested 25-footer to end the Raptors' run. That started a 7-0 run, restoring Atlanta's double-digit advantage.
The Raptors rallied again, with Bargnani's 3 making it 101-97 with 2:57 remaining. Sonny Weems hit a long jumper to make it a two-point game, and the teams traded baskets before Josh Smith deflected a rebound out of bounds to give Toronto possession with 22.6 seconds left.
Hedo Turkoglu drew a foul, but made just one of two free throws. Toronto recovered the rebound and called a timeout with 14 seconds left, and Bosh hit the winner. Crawford's off-balance 3-pointer as time expired was well off the mark.
DeMar DeRozan had 19 points for the Raptors, while Turkoglu added 16.
Raptors G Antoine Wright sat out with a sore right knee, while the Hawks were without scoring leader Joe Johnson (Achilles' tendinitis). ... The Hawks dominated Toronto in their previous two meetings, winning both by a combined 53 points.