OAKLAND, Calif. — On the cusp of pulling a major Christmas Day upset, LeBron James pulled his groin.

The Los Angeles Lakers stunned the Golden State Warriors, 127-101, at Oracle Arena on Tuesday, outworking the two-time defending NBA champions and holding off a second-half comeback, but it was the “pop” the franchise player heard that drew immediate attention.

With the Lakers leading 71-57 at the 8:00 mark of the third quarter, James motioned to his bench to take a timeout, holding his groin in obvious discomfort. As trainers attended to him on the court, James said, “I felt a pop” before departing to the visitors’ locker room.

By early Wednesday morning, the news about the injury seemed less dire, with James telling ESPN that “the good thing is the muscle is intact.” The network reported that James was “in good spirits” and was considered day-to-day, pending the results of an MRI.

The Lakers called the injury a strained left groin. James never returned to the court as his teammates closed out the win. He said afterward that he didn’t attempt a return because he “didn’t feel like it would benefit me or my team,” with a game Thursday night in Sacramento.

James offered no timetable for how long he might be out. Before the injury, the 33-year-old forward had been the game’s central force, posting 17 points, 13 rebounds and five assists in just 21 minutes.

“I was dribbling down the court, and [Warriors forward] Draymond [Green] got his hand on the ball, and I went to get the loose ball and just overextended my groin, I guess,” James said. “I felt it coming down the court and actually overextended it again on defense. Just an unfortunate play.”

For once against Golden State, James was lifted, rather than let down, by his supporting cast. In falling to the Warriors in three of the past four NBA Finals, the four-time NBA MVP saw triple-doubles and 40-point games squandered by Cleveland Cavaliers rosters that lacked talent, depth and awareness. The defining sequence of the end of his second Cleveland tenure came during Game 1 of the 2018 Finals, when J.R. Smith lost track of the time and score in the closing seconds, allowing a 51-point James explosion to go to waste in an overtime loss.

On Christmas, the Lakers not only held on to a lead that James had built, they extended it. Los Angeles closed out the win with a 50-44 margin following James’s injury, with forwards Kyle Kuzma and Brandon Ingram helping carry the scoring load down the stretch. Reserve point guard Rajon Rondo also took the reins of the offense, posting 15 points and 10 assists and forcing Golden State Coach Steve Kerr to pull his starters early with the game out of reach.

“There’s a decent chance we could see the Lakers in the playoffs,” Kerr said. “I think they have gotten a lot better in this first third of the season, but they are making good strides . . . This loss obviously is a smack in the face, and we have to respond.”

From the opening tip, James’s new Lakers teammates looked more energetic and more poised than his former Cavaliers teams. Coach Luke Walton expected the Christmas showcase to be an “unbelievable experience” with “playoff energy” that would test his young team, which missed the postseason in his first two seasons on the sideline.

As the Warriors dawdled in the early going, the Lakers capitalized, sending hard double-teams at Golden State’s stars and daring role players such as Jonas Jerebko and Alfonzo McKinnie to shoot. The strategy worked, and Golden State committed 14 turnovers and shot just 9 for 36 on three-pointers.

The Lakers’ defensive game plan hinged on tightly defending Stephen Curry, Kevin Durant and Klay Thompson at the three-point line by fighting over the top of screens. The Warriors’ top three shooters combined to shoot just 6 for 19 on threes; Curry finished with just 15 points on 17 shots, the seventh time in seven Christmas games he has failed to top 20 points.

“I’m really happy with the mental effort our group gave,” Walton said. “They followed [the game plan], communicated and did the little things. That was probably our most complete game of the season, and there were a lot of good moments to build off.”

As impressive as the Lakers’ signature victory was, James’s uncertain status cast a shadow over the team’s short-term prospects.

“With me and injuries, I’m never too concerned,” James told reporters. “I was able to walk off under my own power. I don’t know [whether I can play Thursday against the Kings]. We’ll see what the MRI says.”

The 14-time all-star has been an ironman in recent years, playing in 156 consecutive regular season and postseason games dating back to the 2016-17 campaign. James played all 82 games for the first time in his career in 2017-18, leading the NBA in minutes during the regular season and the playoffs.

Over his past four seasons in Cleveland, the Cavaliers were 207-94 (.688) with James in the lineup and 4-23 (.185) when he wasn’t. Already this season, the Lakers have enjoyed a LeBron bump: Los Angeles went 35-47 last season but is off to a 20-14 start with James. Even a brief absence could cost the Lakers playoff positioning, given that they are just two games ahead of the San Antonio Spurs, who are currently the West’s ninth seed.

But to the many Lakers fans in attendance for the upset, the mood remained joyous to the final buzzer. They stood, cheered and waved as their Warriors counterparts headed to the exits early. There would be plenty of time to worry after Christmas.