LeBron James strains left groin during Lakers’ rout of the Warriors

Reporting from Oakland —  LeBron James didn’t seem distraught in the postgame locker room. He wasn’t moping or cursing his luck after the Lakers surprised the Golden State Warriors 127-101. He talked about getting back to Los Angeles later Tuesday night, and joked about Christmas gift-giving.

Less than two hours before, James had sent shock waves through his team and all of Lakerland by having to leave the game with 7:51 left in the third quarter due to a groin strain. Initial testing revealed his muscle intact and allayed concerns that it might be a significant injury. James will have an MRI on Wednesday to determine the severity of the injury.

“I wasn’t able to go back into the game, obviously,” James said. “I’ll get an MRI tomorrow and see what’s up.

“With me, with injuries, I am never too concerned about them. I was able to walk off on my own power. I felt a pop and [tried to] see if I could stretch it a few times and see if it will relieve but it didn’t.”

What happened after he left might have helped his mood too. The Lakers had dominated the Warriors with James in their lineup, and without James they gave Golden State a rare thrashing.

The Lakers were led by 19 points from Kyle Kuzma, 18 from Ivica Zubac and 17 from James. James also added 13 rebounds and five assists. Rajon Rondo had 15 points and 10 assists.

Golden State’s Andre Iguodala led all scorers with 23 points, and Kevin Durant added 21. The Warriors made only 25% of their 36 three-pointers, with their starters making six of 23 from beyond the arc.

“We think we can play with anybody,” Lakers guard Lonzo Ball said. “We’re not scared of nobody.”

It was James’ first win in Oakland since the 2016 NBA Finals, and his first regular-season win on the road against the Warriors (23-12) since February 12, 2014, when he played for the Miami Heat.

It’s the first time under coach Steve Kerr that the Warriors have reached 12 losses before the calendar year turned. The Lakers, meanwhile, improved to 20-14.

“That was probably our most complete game this season,” coach Luke Walton said.

The Lakers got off to a good start, taking a seven-point lead after one quarter. Hints of the Warriors’ three-point-shooting problems arose while the Lakers shot well both overall and from three-point range, making five of 10 long-distance shots.

As the second quarter progressed, Golden State kept missing its three-pointers, hounded by the Lakers. At one point, the Warriors had made just three of 19 attempts from deep. At halftime, the Lakers led by 15.

The Lakers built the margin to 19 and led by 14 when it appeared disaster might have struck.

“I was dribbling down the court and Draymond [Green] got his hand on the ball and I went to get the loose ball and just over-extended my groin, I guess,” James said. “And then I felt it coming down the court, I actually over-extended it again back on defense.”

James told training staff he felt a pop and Walton immediately called a timeout. As the team huddled, James stretched, trying to work out the kink. He spoke with his trainer Mike Mancias and Lakers trainer Marco Nunez.

No one expected it when he left the court and headed into the locker room. After all, James hadn’t missed a game since the end of the 2016-17 season — and then it was for rest heading into the playoffs.

“I’ve never really seen him injured,” Kuzma said. “If he has to go to the locker room, you know it’s something serious because he does a hell of a job taking care of his body.”

James went back to the locker room to be examined, and the news was good, according to sources familiar with the examination. Though he hasn’t ruled out playing in Sacramento on Thursday, he also didn’t commit to being available. Walton said the team would prepare to play without James.

James watched from the locker room as his teammates tried to finish what they’d started with him.

“At first they didn’t play very well, they let Golden State go on that 14-1 run, but after that Kuz was able to go to the free-throw line and get some free throws and then we just controlled the pace after that,” James said. “[Rajon] Rondo was gigantic in controlling the pace.”

That 14-1 run cut the Lakers’ lead to three on a running dunk from Durant that caused the Oracle Arena crowd to erupt with 3:22 left in the third quarter. But then the Lakers got their bearings.

A three-pointer from Lance Stephenson to close the third quarter gave the Lakers a nine-point lead and a strong starting point for the final 12 minutes.

“They probably felt a little stronger once he went down,” Rondo said of the Warriors. “But other than that, a lot of us still get paid a nice amount of money to do what we do, and we were able to step up and produce for our team.”

Josh Hart made a three-pointer to stretch the Lakers’ lead to 23 with 3:36 left in the game and the home team’s fans began to leave. Soon, all that remained were Lakers fans, many of whom wore James’ No. 23 jersey, relishing a win after a near-disastrous moment.

tania.ganguli@latimes.com

Twitter: @taniaganguli