BOSTON -- The Boston Celtics were clinging to a five-point lead midway through the fourth quarter when Chicago Bulls forward Bobby Portis launched a wide-open 3-pointer from the corner. The ball clanged hard off the rim, and Celtics big man Al Horford, while sandwiched between Robin Lopez and Jimmy Butler, leaped to snare the rebound.

None of the three players could come up with the ball, but Butler had his fingertips on it as a mad scramble began when it fell to the floor. Lingering near the scrum, 5-foot-9 Isaiah Thomas raced into the pile and, despite being the shortest player by roughly 10 inches, came up with the ball. Thomas swung his arms wildly in trying to prevent it from being stripped away before he was fouled.

Thomas flexed a bit as the Celtics' bench applauded his effort. The sequence was Game 5 of this series in a nutshell: an ugly tug-of-war in which Thomas and the Celtics seemed to want it more in the fourth quarter.

2017 NBA Opening Night On opening night, the Warriors were stunned in Oakland and the Celtics' high hopes took a tumble. • Irving: Hayward injury among worst

• Despite gloom, hopeful signs for C's

• Hobbled CP3 sees Houston rally

• LeBron shakes ankle woes in opener

• Warriors get rings for 2017 title

The rebound was one of the five that Thomas came up with on this night, and he did everything he could to help his team despite an uncharacteristically poor shooting performance. The Celtics pulled away late in the fourth quarter for a 108-97 triumph at TD Garden.

The Celtics lead the best-of-seven series 3-2. Game 6 is Friday night in Chicago.

"One thing about playoff basketball, when [your] shot's not falling, you gotta figure out a way to win," Thomas said. "Tonight we did that."

Thomas struggled to get himself going in Game 5. He missed his first five shots and didn’t register his first field goal until there were 42.6 seconds remaining in the first half.

At halftime, Thomas changed both his headband and his shoes. That he changed his shoes was not particularly unusual. Last season, after a big road win over the Golden State Warriors, Thomas noted in his postgame interview that "them other shoes didn’t have any buckets in them."

Thomas' new kicks had enough buckets in key moments of the fourth quarter to help the Celtics separate from the Bulls. He finished with 24 points on 6-of-17 shooting with those five rebounds, four assists and a steal over 36 minutes.

And he was not called for any discontinued dribbles, much to the chagrin of Bulls coach Fred Hoiberg, who stomped off from his postgame news conference when asked if Thomas had committed any of the infractions that Hoiberg decried after Boston's Game 4 win in Chicago.

Isaiah Thomas and Al Horford celebrate during the second half of the Celtics' Game 5 victory. The pair combined for 45 points. Bob DeChiara/USA TODAY Sports

Unlike in Game 4, when Thomas carried Boston in the second half, the Celtics got balanced contributions. Avery Bradley scored 17 of his career postseason high 24 points in the first half, all while chasing Butler for much of the night. According to ESPN Stats & Information, Butler finished with just two points on 1-of-5 shooting with one turnover when defended by Bradley (Bradley, meanwhile, scored 11 points on 5-of-10 shooting with Butler defending).

Butler even admitted after Game 5 that Bradley had won the head-to-head battle.

"I’m trying to make it hard on him," Bradley said. "Like I said, Butler’s a very good player. And my job for our team is to go out there and defend, try not to foul and make the player work for every shot, make him work on both ends of the floor. And that’s what I tried to do tonight."

Horford quietly did all his usual Horford things. He finished with 21 points on 7-of-11 shooting, nine assists and seven rebounds. He came up with a series of big buckets in the fourth quarter while rolling hard at the rim.

"That’s what we need him to do. He’s a hell of a player," Thomas said. "Even the stat sheet doesn’t explain how good of a player he is sometimes. When he’s not scoring or rebounding, he’s doing a lot of things to help out everybody else on this team, whether that be help-side defense, whether that be making the right play on offense. He’s a complete basketball player. And when he plays like he did tonight, especially in the second half, nine times out of 10, we usually win those games."

BOSTON CELTICS Check out the team site for more game coverage

CHICAGO BULLS Check out the team site for more game coverage

Once down 0-2 in this series, the Celtics head to Chicago with a chance to close out the Bulls. The momentum of the series began shifting when Rajon Rondo was ruled out before Game 3, and Boston has played far more inspired ball since Thomas returned home to be with his family in Tacoma, Washington, following the death of his younger sister.

The Celtics always believed they could rally from their early series deficit.

"I mean, it’s kinda been the story of our team, being able to fight through adversity. No matter what we go through, we would overcome it," Bradley said. "And I think it’s a group of guys, our coaching staff, we believe. We believe in one another.

"I said it earlier: We went to Chicago knowing that we were going to win those games, not hoping. We knew that we were going to take two games, then come here and take care of home. Now it’s our job to continue to play the same way and finish the series in Chicago."