There were fears over Curry's availability in Game 4 after hurting his hand in the closing stages of his side's Game 3 defeat on Wednesday, however, he was healthy and he showed up to help the Warriors avoid a 3-1 slump in the finals.
Steve Kerr made a change to his starting five, dropping Kevon Looney to the bench despite his solid series so far, bringing Otto Porter Jr in and moving Draymond Green to center.
Porter only played 14 minutes, with Looney playing 28, meaning there wasn't too much of a change in style for Golden State.
Kerr also made a big decision in the final quarter, pulling out Draymond Green as he looked for an offensive spark. With Golden State down five at the time, it was clearly a superb piece of coaching.
The Celtics went into the half up five but the Warriors came out swinging in the second half, winning the third quarter by six points and the fourth by nine, winning by ten points in the end thanks to Curry's 43.
Robert Williams III had a couple of emphatic blocks and the Celtics' big three had a solid night of scoring. Jayson Tatum dropped 23, Marcus Smart 18 and Jaylen Brown 21, meanwhile, Derrick White had 16 off the bench.
As for Curry's supporting cast, Andrew Wiggins had 17 points and 16 rebounds, Klay Thompson had 18 points and two blocks, Jordan Poole 14 off the bench, and Curry had 10 rebounds to go alongside his monstrous 43-point haul.
When asked to rank Curry's performance out of all his Finals appearances, Thompson said: "Probably number one.
"It was nearly a must-win game, so to go out there and shoot as efficiently as he did and grab 10 rebounds all while they are attacking him on defense? His conditioning is second to none in this league.
"Steph played incredible."
Green echoed his teammate's comments: "He put us on his back and willed us to win.
"Much-needed win, a game we had to have, and he came out and showed why he's one of the best players to ever play this game and why this organization has been able to ride him to so much success."
"I don't rank my performances," Curry said. "Just win the game."
Warriors coach Kerr added: "Whenever I'm done coaching, I will look back and say thank you to Steph because night after night he has made this situation for us as an organization easy for everybody.
"He's a special player, special person."
The series is all tied up at 2-2 and has become a best-of-three battle. Game 5 takes place at the Chase Center on Monday evening.