If the script this season calls for comebacks, the Celtics are playing their roles to the hilt.

Paul Pierce was the protagonist again, this time in the most dramatic of last-second fashion.

For the second time in three days, Pierce (34 points) bailed out the Celtics in the final quarter, his jumper with 0.5 seconds on the clock providing the difference in a 103-102 win over Atlanta in a showdown of Eastern Conference leaders Wednesday night.

As in Monday's 94-87 win over Toronto, the Celtics (8-1) were nearly buried before digging themselves out of a 16-point hole in the first half against the Hawks (6-1). But the Celtics struggled to clinch this victory, despite having the Hawks fluttering in the second half without Zaza Pachulia (shoulder), who started in place of Josh Smith (ankle sprain).

In fact, the Hawks nearly pulled this one out, taking the lead on Marvin Williams' 3-pointer with 7.4 seconds to go. Then, the Celtics set up Pierce off a Kevin Garnett screen, Pierce going to the right of the lane, just in front of the Celtics' bench, lofting a 16-footer over Al Horford.

"Once I went right, I had the big guy (Horford) on me, I sort of got to my sweet spot," Pierce said. "The play was to get the ball to Kevin, and if they switched off, either hand off or he would take the drive down the lane. But they switched and put Horford on me and I knew I could get to my spot."