You can never count this team out. They never stop fighting and they always make things interesting. However, the Hawks were able to hold on and win game one of the playoffs.
Things couldn't have gone much worse in the first half. The Celtics couldn't hit outside shots, so they tried layups and that didn't work either. They trailed by as many as 19 points. That's too much of a hole to dig out of in the playoffs.
The 2nd half was another matter. The Celtics played their kind of basketball, locking down the Hawks, creating turnovers that led to fastbreak points, and hitting closer to their average from the field. They came all the way back and even took a brief lead.
Avery Bradley left the game with a pulled hamstring and he was missed on the court. Hopefully he'll be able to recover in time to be a factor in this series.
Down the stretch the Celtics got huge plays from Marcus Smart. He hit a couple of big 3 pointers, created a turnover, and grabbed a big rebound. However, it wasn't enough as the Hawks made some big buckets and the Celtics missed some wide open 3 point shots. Granted, those shots were taken by guys like Marcus Smart and Evan Turner - not normally known for shooting well from outside.
The Hawks simply executed better than the Celtics when they needed to.