OKLAHOMA CITY -- Add another contender to the Oklahoma City Thunder's list of impressive recent conquests.

The Thunder built a big lead over Boston and held off a late comeback bid for a 127-123 win Tuesday night over the Celtics, owners of the NBA's best record.

Oklahoma City has won eight of its past nine games, putting the Thunder second in the Western Conference at 23-9. That span has featured wins over elite competition, including the first-place teams from both conferences (the Minnesota Timberwolves and the Celtics) and the defending champion Denver Nuggets, who Oklahoma City beat twice on the road.

"That's a talented young team, and I don't believe this was some fluke game for them," Celtics center Kristaps Porzingis said after his 34-point, 10-rebound performance wasn't enough to prevent Boston's six-game winning streak from being snapped. "They've been playing really well. They're at the top of the West, no? So a really good team to go up against and a really good experience for us."

The Thunder's five-game winning streak includes a 23-point home blowout of the Timberwolves and a 26-point road rout of the Nuggets. Oklahoma City seemed to be on the verge of another lopsided win over the Celtics, going up by 18 with 8:25 left in the fourth quarter.

Oklahoma City, which has the second-youngest roster in the NBA, is putting together a case to be considered a contender, following up a 14-win improvement last season at 40-42. The Thunder own the league's fourth-best record, rank third in net rating (plus-8.5), fourth in defensive rating (110.7) and fifth in offensive rating (119.2).

The Thunder, however, have no interest in discussing whether they already belong in the contender conversation.

"It says that we're really playing together and we're prioritizing winning over anything else," Rookie of the Year front-runner Chet Holmgren said of the Thunder's strong run after his 14-point, 7-assist, 4-block contribution Tuesday. "But as far as long term, it doesn't really prove anything, I guess you could say, or it doesn't kind of satisfy anybody.

"We know we have a long ways to go. We're at 32 games into the season, so we still have 50 games left. We got a lot of lessons to learn, a lot of lessons we've already learned from that we've got to kind of keep in the back of our mind."

Oklahoma City superstar Shai Gilgeous-Alexander, the league's third-leading scorer, had another spectacular performance with 36 points on 14-of-22 shooting. However, his only points in the fourth quarter came on a few free throws as the Celtics whittled away at the lead, making it a one-possession game in the final minute.

Gilgeous-Alexander's biggest plays down the stretch were feeding center Holmgren for a 3-pointer with 2:06 remaining and setting a screen to free forward Jalen Williams for a driving floater with 26 seconds left.

"He's learned how to impact the game in other ways and that's why he's a really good player," Thunder coach Mark Daigneault said of Gilgeous-Alexander, who also had six rebounds and seven assists. "He's not just a hired-gun scorer."

Daigneault referred to the last several minutes of the game as "sloppy" for the Thunder, a description some Oklahoma City players echoed. They also expressed belief that having to fight down the stretch to pull out the win over the Celtics presented some of the lessons Holmgren referenced.

"I think we all stay in the moment and I think that's why we've been able to get better," Gilgeous-Alexander said. "We just stay in the moment, attack the day, attack the program in front of us. Then we all have the right intentions and want to win at the end of the day."