Boston -- Al Horford may have been there and done that, but not here and not this.

Not at this level anyway.

AP (ENLARGE)

Hawks forward Al Horford misses the dunk with four Celtics anticipating the rebound. Horford lead all Hawks with 20 points, 10 rebounds.

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Were the ramifications the same at the pro level as in college basketball, he'd be home today and looking forward to next season.

As it is, he was the only Hawks starter to thoroughly acquit himself Sunday night in Game 1 of the Eastern Conference playoff series against Boston. He led Atlanta in points and rebounds with 20 and 10 found a silver lining after his first postseason loss since 2005: he and his teammates get another shot -- at least three, in fact -- against the Celtics.

Who said drawing a paycheck was the only good thing about the NBA?

"Obviously the similarity [in college and pro postseasons] is a different atmosphere from the regular season; you can feel it in the air," he said after Atlanta's 104-81 loss. "But as far as other differences, you have to come back and play. It's the best-of-seven here. In school, our mentality was win or go home. Here, we have a chance to redeem ourselves and play another game."

For that to happen, Horford will need more help Wednesday.

He made 7-of -10 shots Sunday, but his teammates combined to make 22 of 66, and his fellow starters were good on just 14 of 49 (28.6 percent).

You wouldn't have known from watching Sunday that Horford is a rookie center, that he's playing out of position, or that the natural power forward was in his first NBA postseason game. Either he's sage ahead of his time, or he had so close a look at the problem it was impossible to miss.

"We definitely didn't shoot the ball," he said. "We would have liked to have made some open looks."

Horford was central to two national championship teams for the University of Florida the past two years, and did not look like a greenhorn Sunday. He played as if he had playoff experience, apparently leading the Hawks not only in scoring and rebounding, but perhaps focus as well.

Defensively, he had some issues, but while giving up a couple inches while guarding Celtics forward Kevin Garnett much of the night (never mind that the program lists Horford as 6-feet-10 and Garnett at 6-11), he helped harass the potential league MVP into an 8-for-19 shooting night.

When the game all but written off, Horford did not go quietly into the night in the final quarter.

First, he kept a ball alive on the offensive glass, and finally grabbed a rebound only to be fouled. He made 1-of-2 free throws on the way to making 6 of 7 overall. Horford added two assists, a steal and a blocked shot.

On the next possession, he grabbed another offensive rebound in the lane while spinning his back toward the basket, spun and rose again to make a short jumper. Sadly, all that did was pull the Hawks to within 91-71.

Had a few -- OK, several -- Hawks players been as efficient as Horford, this game might've been considerably closer.

"He was unbelievable, Hawks coach MikeWoodson said. "He played like he has been playing playoffs all season."

Horford doubled his season scoring averaging of 10.1 points, but when the Celtics re-calibrated their offense in the second half, when as Boston's Paul Pierce said, "We started making the extra pass," the hinges of the Hawks' offense went loose.

Rookie or not, even Horford saw the sum total -- that many of his mates played like they had never been here before, here being the NBA postseason.

"It was one of those things where it was the first experience for the team in the playoffs," he said. "We have to understand we have to stay together and stay strong out there. Teams are going to make runs, but we've got to be able to make runs back."