Jayson Tatum scored 20 of his 27 points in the second half and the Boston Celtics rallied in the fourth quarter to beat the Oklahoma City Thunder 111-94 on Saturday night.

Jaylen Brown added 25 points to help the Celtics close out a four-game trip and even their season record. Boston had lost five of six before winning at Milwaukee on Friday and at Oklahoma City on Saturday.

"We feel good," Celtics guard Marcus Smart said. "We don't feel great. We don't feel like -- we're not complacent. We're not done. We're not satisfied. This is just a start for us."

A loss would have damaging for a squad that has struggled to find consistency this season.

"This was one where we had to find a way because we can't keep going back and forth," Celtics coach Brad Stevens said. 'We've got to establish some momentum here."

Moses Brown scored a career-high 21 points and tied a Thunder record with 23 rebounds. The team announced before the game that veteran center Al Horford will be inactive the rest of the season while the team's young players develop. Brown moved into the starting lineup and set a franchise record for rebounds in a half with 19 before the break.

"I just wanted to come out and set the tone with my energy and just being active around the basket," he said. "Just knowing how to get space and knowing how to box out and utilizing my height and my strength."

Theo Maledon added 22 points for Oklahoma City.

Brown had 17 points in the first half as the Thunder took a 52-47 lead. He made 6 of 6 field goals and 5 of 6 free throws in just 16 minutes.

The Thunder led 80-76 heading into the fourth quarter. Jaylen Brown kept the Celtics in it with 13 points in the third.

Back-to-back 3-pointers by Luke Kornet put the Celtics up 88-82 early in the fourth. The Celtics acquired Kornet from the Chicago Bulls in a three-team deal that involved the Washington Wizards.

A fast-break dunk by Tatum put the Celtics up 95-82, and Boston cruised from there. The Celtics shot 56% in the fourth quarter and outscored the Thunder 35-14. Oklahoma City made just 5 of 17 shots in the final period.

The fourth quarter offered a glimpse of the way the Celtics want to play the rest of the season.

"We've got a lot of talent out here individually, but that's not going to beat anybody," Smart said. "That's not going to beat teams. Teams are getting better, teams are good, teams are doing their homework."

TIP-INS

Celtics: Evan Fournier, a guard who joined the Celtics in a trade with the Orlando Magic on Thursday, was out because of health and safety protocols. He's averaging 19.7 points and 3.7 assists. ... Guard Kemba Walker rested. ... Center/forward Robert Williams had 14 rebounds.

Thunder: Guard Austin Rivers is not with the team. He was acquired from New York in the three-way trade that sent George Hill to Philadelphia. ... Thunder G Shai Gilgeous-Alexander remained out with plantar fasciitis in his right foot. ... All five starters - Brown, Maledon, Lu Dort, Aleksej Pokusevski and Isaiah Roby - are in their first or second year.

GOOD COMPANY

Moses Brown joined Steven Adams, Serge Ibaka, Nick Collison, Russell Westbrook, Shai Gilgeous-Alexander, Enes Kanter and Shai Gilgeous-Alexander as the only Thunder players to grab 20 or more rebounds in a game. He tied Adams' single-game rebounding record, which was set Dec. 19, 2018 at Sacramento. Adams also had the record for rebounds in a half with 15, in the same game against Sacramento.

QUOTABLE

Horford on his status: "When I arrived, I understood the direction of the team, we had a great individual plan in place for me, and I feel like as a result I've played really good basketball for the Thunder. At the same time, I know what it's like to be a young, aspiring player, and at this point in the season I understand how important playing meaningful minutes is for their careers and their development."

UP NEXT

Celtics: Host New Orleans on Monday night.

Thunder: Host Dallas on Monday night.