Klay Thompson admitted he "fell asleep" as the Utah Jazz produced a stunning finish to snatch a dramatic 124-123 win over the Golden State Warriors on Wednesday.

The Warriors roared back from 11 points down in the fourth quarter to lead by four with only 13.3 seconds to play at Vivint Arena.

Golden State paid the price for switching off in the closing stages, though, leaving Malik Beasley on his own in the right corner to give him the chance to land a three-pointer.

Simone Fontecchio then came up with a decisive dunk with 1.4 seconds to go after Utah forced a turnover from Jordan Poole.

Thompson held his hands up for not paying close attention to Beasley.

"I just fell asleep," Thompson said. "I watched the ball handler get to the rim rather than sticking on the three-point shooter. That was a dreadful mistake by myself."

Poole, who scored 36 points and provided eight assists, was at a loss to explain what happened late on.

"I heard on the catch, 'Look for the foul on the ball'," Poole said. "I don't really know [what happened], to be honest."

Warriors head coach Steve Kerr expects his team to learn from a shattering defeat.

"I feel terrible for our guys because they fought and they did a lot of great things, but we have to close the door," Kerr said.

"I thought [we] really fought and earned the right to win the game, and then we didn't close. And you've got to close.

"You've got to be rock solid with the ball. You've got to be smart defensively. We were neither of those things the last 13 seconds."

Golden State are 10th in the Western Conference at 13-13 after back-to-back losses, with the 15-12 Jazz four places above them.