Jayson Tatum pushed the Celtics to OT, and Jaylen Brown pushed them to a much-needed win over the Pacers

Celtics forward Jaylen Brown (center) drives to the basket between the Pacers Jeremy Lamb (left) and Myles Turner (right) during the first half of Monday night's game at TD Garden.Jim Davis/Globe Staff

A couple of months from now, when the Celtics hope to be battling for a preferred playoff position, the details of this night will not matter or even be easily remembered.

The Pacers were without three of their top five scorers and mostly left to rely on veteran reclamation project Lance Stephenson for their offense. The Celtics were at home and had nearly their entire roster available.

Both teams spent more than two hours playing an ugly and low-energy game, and when Boston trailed by four points with less than a minute left in regulation, it appeared that it would ultimately need to explain yet another confounding loss.

This time, though, the Celtics rallied before it was too late, as Jayson Tatum sent the game to overtime by drilling a long jumper with 1.8 seconds left in the fourth, and Boston ultimately eked out a 101-98 win at TD Garden.

It was not artistic, but for a team that has already dealt with a season’s worth of fourth-quarter misadventures filled with bad bounces, bad execution, and bad luck, the Celtics will take what they can get.

“I’m looking at the positives tonight of gutting one out,” said Celtics coach Ime Udoka, “when it’s gone the other way several times this year.”

Just two games ago, the Celtics were stunned as the Knicks stormed back from a 25-point deficit and grabbed an unlikely win when RJ Barrett banked in a deep 3-pointer at the buzzer. That dropped Boston to a season-worst three games under .500, and it all but put its season on the brink.

But these last two wins have pushed them to 20-21 at the midway point. Although that is certainly not the start this team once envisioned, there is also a sense that things could have been worse. And now that the Celtics are mostly healthy again, perhaps they can nudge back into the conference’s middle tier. At the very least, Monday’s win was far better than the alternative.

Jayson Tatum hits a two-pointer in front of the Pacers' bench at the end of regulation to tie the game and send it into overtime. Jim Davis/Globe Staff

“It felt great,” Tatum said. “That would’ve been—that one would’ve hurt had we lost. But throughout the course of the season it feels good to figure games out like that.”

Jaylen Brown had 26 points, 15 rebounds and 6 assists to lead Boston. Tatum added 24 points and 12 rebounds but made just 7 of 21 shots and committed eight turnovers. Boston had 20 turnovers as a team, which would generally provide the latest example of their crummy late-game execution.

In this case, though, the Celtics actually held up pretty well down the stretch and made things quite difficult for the Pacers by swarming star big man Domantas Sabonis (11 points, 23 rebounds, 10 assists) in the paint and forcing lower-level perimeter players into tough, contested attempts.

Indiana's Domantas Sabonis grabs a rebound in front of Robert Williams III during the second half of Tuesday's game.Charles Krupa/Associated Press

“I think as much as we weren’t sharp in certain areas tonight, I think the overtime and fourth quarter when we needed to get stops, that was some of our sharpest execution on both sides of the ball,” Udoka said. “I think offensively, we got the shots we wanted in the overtime and we really locked in, held them to late shot clock situations several times in overtime. So I felt good about that execution, and we’ve been in enough of these tight games to start seeing improvements as a positive.”

Robert Williams added 14 points,12 rebounds and 3 blocked shots for the Celtics. Marcus Smart left the game midway through the third quarter because of a thigh contusion and did not return.

The Celtics led by as many as 12 points in the third quarter, thanks in large part to a Pacers scoring drought that stretched for more than five minutes. But Boston probably should have grabbed a bigger lead during that stretch. Instead, the Pacers lingered.

A Sabonis dunk with 5:57 left in the fourth gave the Pacers a 75-74 lead, their first since 6-4.

Indiana had the ball and an 89-87 advantage when Stephenson missed an 18-footer with 15 seconds left. Boston elected not to call a timeout, and an unsettled possession ended with Tatum’s pass being knocked out of bounds with 6.2 seconds remaining. That gave the Celtics a chance to reset, and it gave Tatum a chance to settle in and drill a tough baseline jumper, tying the score with 1.8 seconds to play.

After a timeout, Justin Holiday was forced to double-clutch on a contested corner 3-pointer, and it caromed long off the rim, leading to overtime.

Grant Williams brings the crowd out of their seats after he hit a clutch three to give Boston a 96-91 lead in overtime.Jim Davis/Globe Staff

“It’s something that I work on all the time, every day,” Tatum said. “So took what they gave me and it went in.”

The Pacers pulled within 98-95 on a Sabonis layup with 47 seconds left in the extra session, and at the other end Tatum committed his eighth turnover. But Stephenson’s potential game-tying 3-pointer with 8 seconds left was off.

Brown was fouled and made one of two free throws, seemingly ending the game. Then Josh Richardson was charged with a foul on Holiday’s 3-point attempt with 3 seconds left. He made the first two and tried to miss the third, but it caromed in off the glass. Tatum was fouled and hit both free throws, and the Pacers full-court inbounds pass was intercepted by Williams.