The Hawks acted fast.

With home-court advantage in the playoffs within their grasp, they wasted little time in grabbing the postseason edge. Thanks to a fast and furious first quarter the Hawks will open their Eastern Conference playoff series against the Celtics at Philips Arena.

The Hawks led by as many as 23 points in the first quarter and disposed of the defending NBA champion Mavericks 106-89 on Thursday night in the regular-season finale.

There was no need to scoreboard-watch the Celtics-Bucks game. The Hawks knew if they took care of their own business, it wouldn’t matter what was happened in Boston.

“Personally, I want the home court,” Hawks coach Larry Drew said before the game. “I think that is important for this ballclub. We set out at the very beginning to try to play as well as we can and see where we were from a playoff standpoint. I’ve said it before after we lost Al [Horford], the question was could we make the playoffs.

“But we were able to band together and position ourselves in the playoff race. Lo and behold, we have an opportunity to solidify home-court [advantage]. We put ourselves in this position. I think it’s important that we go after it.”

That they did.

The Hawks (40-26, 23-10 home) enter the playoffs having won five of their final six regular-season games. They snapped a three-game losing streak to the Mavericks.

The Mavericks (36-30) enter the Western Conference playoffs as the seventh seed and will begin a first-round playoff series against the Thunder on Saturday.

Josh Smith did much of the early damage for the Hawks. He finished with a game-high 23 points and nine rebounds, one rebound shy of his 29th double-double this season. The Hawks had five other double-digit scorers: Jeff Teague (17), Joe Johnson (15), Kirk Hinrich (12), Willie Green (11) and Ivan Johnson (10).

Dirk Nowitzki led the Mavericks with 22 points.

The Hawks came flying out of the gate and built the 23-point first-quarter lead, 36-13. The used a 13-0 run early in the quarter and didn’t let up. They ended the first 12 minutes with a 38-21 lead as they shot 69.6 percent (16-for-23) from the field. Seven different players made the scoring column, led by Smith with 12 points.

The Mavericks, by stark contrast, struggled from the field. They shot just 33.3 percent (7-for-21) from the field.

The Hawks led by 16 points, 60-44, at the end of the first half. By then, they had nine different scorers, led by Smith with 16 points and Johnson with 11.

“Not saying that it could be a difference-maker in a series, but any team that is vying for positioning certainly wants to start on their home court,” Drew said. “We are no different. We are in a position where we can control our destiny from a playoff position and here we are staring it in the eye, so why not go for it.”

The Mavericks got within 11 points, early in the third quarter, but the Hawks never let their wide margin get below double-digits.

The Hawks can now rest — at home — before opening their fifth consecutive postseason. This will be their time to rest, a luxury the Celtics took last week.

“One of those days [off] will certainly be just a mental day,” Drew said. “No banging. No real stuff on the floor. We’ll spend most of our time watching tape and having meetings.”

With four minutes remaining, the Philips Arena crowd began the “We Want Boston” cheer. They will be in town Sunday.