Watson dominated the fourth quarter, when he scored eight points on 3-for-3 shooting and handed out eight assists.
The Jazz scored 11 field goals in the final 12 minutes, meaning Watson had a direct hand in every one.
"He was going good, man," said Corbin. "He was directing our offense very well. He was up on the ball on the defense end. He was challenging them and putting a lot of pressure on them."
Corbin didn't consider subbing for Watson not after he sparked a 14-0 run that gave the Jazz an 83-68 lead with 6:18 remaining.
"He was hurt," said Corbin. "If I took him out, I wouldn't have been able to put him back in, I don't think. So, while he was going good, I just wanted to use him. He did a tremendous job."
At the morning shootaround, Corbin saw Watson's ankle and did not expect to him play: "He said, 'I'll be all right.' But his ankle was puffy."
Before tip-off, however, Watson told his coach he was available.
"That's the way he is," Corbin said. "He's a true, true professional. He's a tough guy that wants to be on the floor and help his team win. You saw that tonight.
"I knew he was in pain. He had to be, from what I saw [Saturday] morning. But he fought his way through it. I just have tremendous respect for the guy."
Watson injured his ankle in Wednesday night's 107-105 loss to the Clippers, when he landed on teammate Enes' Kanter's foot.
Watson accompanied the Jazz to Golden State for Thursday's 119-101 loss to the Warriors, but he left before the game to get treatment in Los Angeles.
"I knew I was going to play," Watson said. "That's why I went to L.A. to get treatment, so I could play."
Asked if he was surprised how effective he was against the Lakers, Watson shook his head and said: "I wasn't surprised. I've been going to this doctor for 14, 15 years. So I wasn't surprised at all."
Watson triggered a decisive play in the game.
The Jazz owned a 72-68 lead with 8:41 left when he stole the ball from Pau Gasol near the top of the key and fed Derrick Favors for the layup.
Lakers coach Mike Brown, incensed that Watson was not called for a foul, picked up to two technicals for charging onto the court and protesting.
When the sequence ended, Utah enjoyed a 75-68 lead and the non-sellout crowd of 19,642 had been whipped into a frenzy.
"Pau was dribbling," Watson said, "and I stole the ball. It was a loose ball. Somehow, Pau fell down. I didn't push him. I guess they thought I pushed him."
Watson kidded Favors in the locker room, wondering why the Jazz's young power forward modestly dunked the ball at the end of the fast break.
"I thought Favors was going to give me something spectacular," Watson said. "But he did the old-school, double-dribble dunk. Old school. I was like, 'Come on, man, that's like [you're] 10 years old. I could have done that.' "
The Jazz snapped a two-game losing streak by beating Los Angeles, where UCLA product Watson attended college. But he didn't take special joy in defeating the Lakers.
"I like beating every team," Watson said. "I love winning every game. I feel like we can win every game. Maybe I'm just an optimist sometimes and it's not real. But that's the way I am the way I'm wired. ... Win every game."