Former Celtics coach Doc Rivers used to bemoan members of his team trying to play Hero Ball, a brazen solo attempt to hijack the outcome of the game by a single player. These Celtics employ an embraceable version of Hero Ball. Anyone and everyone can be the hero on the NBA’s ultimate ensemble group.

It was fitting that the most egalitarian of NBA teams needed nearly everyone and everything it had to even their first-round playoff series with the Atlanta Hawks, scoring a pulsating 104-95 overtime victory on Sunday at TD Garden to reset the series, 2-2, headed back to Atlanta for Game 5 on Tuesday.

In 53 minutes of pulse-pounding, cardiac-challenging playoff basketball, the Celtics overcame the virtuoso performance of Atlanta’s Paul Millsap, who dropped 45 points and grabbed 13 rebounds, with a group effort. This victory said more about the Celtics’ ability to win in the playoffs with their brand of basketball than Game 3, which featured Isaiah Thomas burning the Hawks with a 42-point performance. This was the apotheosis of the Brad Stevens Celtics.

On Sunday, oft-maligned guard and flop aficionado Marcus Smart redeemed himself by scoring 11 of his 20 points in the fourth quarter and finally turning off the spigot on Millsap’s scoring deluge with hard-nosed defense. Jonas Jerebko scored 15 of his 16 points in the second half, when the Celtics had to recover from a 16-point deficit. Amir Johnson delivered the Celtics first 5 points of overtime. Thomas delivered the dagger with a corner 3-pointer in overtime that put the Green up, 102-95 with 30 seconds left in overtime.

If any of them had faltered the Celtics would have been staring at a 3-1 series deficit and playoff elimination. Instead, in the span of three days and two games in Boston, the Celtics went from being questioned about whether they could win a playoff game their way to being two wins away from winning their first playoff series under Stevens.

“We wear those shirts that say, ‘We’re one superstar,’ and you never know who is going to have it going,’’ said Jae Crowder. “Guys really stepped up and made one big play after [another] big play — Jonas and Evan [Turner], all of us.’’

Game 4 of this Eastern Conference first-round series was a delightful display of playoff basketball, taut, tense, and raucous. This game took your breath away. It kneaded your emotions until they were stretched string-cheese thin. It will also have the Hawks ruing the fact they didn’t mind the time.

We’re not reveling in the fact that the parquet will be rolled out at least one more time this season if not for a stupefying final possession of regulation from the Hawks and reigning NBA Coach of the Year Mike Budenholzer.

The Celtics trailed, 92-90, with 20.2 seconds to go and the ball, after Hawks guard Jeff Teague canned a pair of 3-pointers in 29.2 seconds to erase a 90-86 Boston lead. Boston inbounded the ball to Thomas (28 points), who flipped it in to tie the proceedings with 15 seconds to go.

The Hawks then ran a horrendous last-shot sequence that ended with Teague holding the ball too long and failing to get off a good shot. It was a baffling and irredeemable final possession that somehow failed to feature a play that ever intended to get the ball to Millsap.

“Jeff had the opportunity to take a guy. He had a good look, but the ball slipped out of his hand,’’ said Millsap. “The play was [designed] for him to be aggressive and try to make a play for us. He made some big shots down the stretch, so we trusted him to win the game for us.’’

This was John Farrell-esque strategy from the Hawks, and it could cost them the series. How about you give the ball to the guy who has 45 points? If Atlanta weren’t our nation’s bastion of sports apathy they would be overloading the phone lines of their local sports talk radio station.

For most of this contest, Millsap looked vaguely like another power forward from Louisiana Tech, Karl Malone. He was so good that he scored, even when he wasn’t really trying to, like a third-quarter basket where he sliced through the paint looking to pass and then just flung the ball at the rim. It went in, along with 18 of his other 31 shot attempts.

“He deserves a lot of credit for that performance,’’ said Stevens. “Millsap was awesome.’’

Game 4 was the first game in the series where one of the teams didn’t break away in the first half.

This time, it was all nip-and-tuck basketball, save for a stretch in the third quarter when the Hawks built a 16-point lead that disappeared in the blink of an eye.

Millsap, who had scored just 12 points total in Games 2 and 3, scored 17 of the Hawks’ 18 points during a stretch in which they turned a 41-38 deficit with 2:32 left in the first half into a 56-46 lead with 9:20 left in the third quarter.

Fueled by Millsap, the Hawks opened the third quarter by scoring the first 14 points to take a 62-46 lead.

But the Celtics whittled that lead down to 73-70 by the end of the third, thanks to a Jerebko three.

“We have a group of guys that have just always been counted out their entire life, so when you’ve been counted out you’ve never been given anything. We just keep fighting,’’ said Thomas. “We continue to fight. We keep believing in each other and stuff usually works out in our favor.’’

The series appears to have turned in the Celtics’ favor as it returns down South. The Green have earned a few playoffs stripes and proven that their one-for-all, all-for-one approach is applicable to the playoffs, too.

The NBA is still a league where talent supersedes togetherness. The Celtics can’t win a championship with glorious gestalt. But they can win a playoff series.

Hero ball isn’t such a bad thing.

Christopher L. Gasper can be reached at cgasper@globe.com. Follow him on Twitter @cgasper.