The Thunder swept Boston in the season series. Their next meeting would be in the NBA Finals

BOSTON (AP) - The Oklahoma City Thunder clinched a spot in the playoffs, and they did it against the team they could face when the NBA postseason reaches its peak.

Shai Gilgeous-Alexander scored 34 and Chet Holmgren added 23 points and 15 rebounds to lead the Thunder to a 118-112 victory over Boston on Wednesday night in a much-anticipated potential NBA Finals matchup.

"We're in March, not June," Thunder coach Mark Daigneault said after the Thunder swept the two-game season series against the defending champions. "So we're focused on March."

The Thunder also beat the Celtics in Oklahoma City on Jan. 5 in a game that Holmgren missed with an injury.

If they meet again this season, it would have to be in the NBA Finals.

"They've achieved what we're trying to accomplish, and there's no better test than that in the NBA," Gilgeous-Alexander said. "Playing against them is always fun, it's always a really good challenge, and something that we could test ourselves against. I guess we passed the test so far."

The Thunder were the second NBA team to clinch a playoff berth this season; Cleveland, which is one win better, earned its spot on Friday. Last year, the Thunder clinched a spot in the postseason on March 31.

"It means we got better than we were last year. Ultimately, that's all you can ask for," Gilgeous-Alexander said. “You put the work in, put the time in … we took steps in the right direction. We got better and we, I guess checked a goal off the list a little bit earlier than last year, and we have a lot more to do."

The Celtics, who rode their 3-point shooting to an unprecedented 18th NBA championship last season, set a franchise record with 63 3-point attempts on Wednesday. It tied the most ever for an NBA team in a regulation game.

"Every game's a test," said Daigneault, whose team was coming off a split in back-to-backs against 2023 NBA champion Denver. "We can't choose the opponent, but when you play against elevated teams like this - especially on the road - it's a real opportunity to improve. And so we take these games seriously.

"We want to see what we have. We want to see what we can learn. We won tonight; we can learn from that. We lost the other night; we can learn from that," he said. "But, yeah, we have to squeeze all the juice out of all these games that we can."

Jayson Tatum scored 33 points for Boston, including a 3-point play at the end of the third quarter that erased the remnants of a 12-point Thunder lead and tied the game 88-all. The Celtics went 3 for 14 from 3-point range from there, while Gilgeous-Alexander and Cason Wallace scored eight points apiece in the fourth quarter.

"Obviously, there's always added juice to the game playing the defending champions. I think anybody would say that," Holmgren said. "But at the end of the day, it’s one of 82. Win or lose, we’re going to try to learn from it, come back next game and try to be better."