James delivered his highest single-game points tally since joining the Lakers in a pulsating battle with the Warriors, who themselves are in a mini-slump that now runs to four straight defeats.
A see-saw game at the Lakers' newly renamed Crypto.com Arena saw the lead change hands nine times, with the Lakers jumping out to a 14-point lead in the first quarter before the Warriors hit back with a 42-point second quarter display.
That left the Warriors in the driving seat and leading by 14 before James and the Lakers gradually worked their way back into the contest with a late burst of scoring in the fourth quarter.
James, who finished with 56 points and 10 rebounds, said afterwards that "desperation" had inspired the Lakers.
"Just desperation," he said. "We needed this win for sure. It means a lot.
"Obviously they're the second best team in the West. They've been struggling a little bit of late, but we've been struggling all year pretty much.
"For us to get a win like this in front of our home fans -- they deserve it. We haven't played like much of anything of late so it's good to get a win like that in front of them."
James hopes the win can act as a catalyst for the Lakers' troubled season. The 2020 NBA champions remain out of the automatic playoff places and are ninth in the Western Conference with a 28-35 record.
"We've gotta see where we can take it from here," James said. "We've got a two-game road trip coming up so let's see what we can do."
Lakers coach Frank Vogel meanwhile saluted James' leadership.
"He leads us with his consistent demeanor, trying to get better every day," Vogel said. "What he did tonight was spectacular."
Heat too hot for Sixers
James' scoring was backed with 20 points from Russell Westbrook while veteran Carmelo Anthony added 14 off the bench.
Stephen Curry led the Warriors scorers with 30 points while Jordan Poole added 23.
Elsewhere Saturday, Jimmy Butler scored 21 points as the Miami Heat shut down Joel Embiid to end the Philadelphia 76ers' five-game winning streak with a 99-82 victory.
The much-anticipated duel between the first and second-placed Eastern Conference rivals was a mostly one-sided affair with the Sixers weakened by the decision to rest star new recruit James Harden.
That left Sixers big man Embiid isolated as the Heat's defense took control to restrict the Sixers scoring, including a season-low 14 points in the first quarter.
Butler was one of four Miami players to finish in double figures.
Tyler Herro added 21 off the bench, while Gabe Vincent finished with 16 points and Caleb Martin 14.
Embiid led the Sixers, scoring 22 points, while Tyrese Maxey finished with 17 points and Tobias Harris 16 on a disappointing night for the visitors, who looked weary after facing Cleveland at home on Friday.
Save for a brief moment in the opening minute of the first quarter, Miami led from start to finish, racing into a 20-point lead early in the second quarter.
"We wanted to set the tone and make a statement and we were able to do that and come out with a win," said Heat point guard Vincent, paying tribute to Heat talisman Butler's performance.
"Jimmy does what Jimmy does ... our leaders led, and we followed," Vincent said.
The win saw Miami improve to 43-22 at the top of the Eastern Conference standings.
Philadelphia remain in the second spot with a 39-24 record.
In other games, Ja Morant and Desmond Bane scored 25 points and 24 points respectively to lead the Memphis Grizzlies to a 124-96 blowout over the Orlando Magic.
The win puts the Grizzlies' into second place in the Western Conference, improving to 44-21.