“This is unbelievable,” Gauff said during the post-match trophy presentation. “I’m just happy to be here for this moment.
“I want to congratulate Karolina for an incredible run in this tournament,” she added. “Hopefully, we’ll play more often, and on a bigger stage than this.”
Gauff was the tournament’s fourth teenage finalist and first since Vera Zvonareva in 2004. She is the first teenage champion since 17-year-old Linda Tuero in 1968.
Top-ranked Carlos Alcaraz and No. 2 Novak Djokovic played for the men’s title in a rematch of Alcaraz’s victory in the Wimbledon final.
After a spotty first set that featured a combined five service breaks, including Gauff’s double fault on one game point, Gauff gained command over her Czech Republic opponent with a break in the eighth game.
She fought off two break points in the fourth game of the second set and took control with a break in the next game when Muchova sent a backhand wide. While winning the next game, Gauff caught a break with a winner off the net that left her with her left palm on her racket and looking up at the sky as if she was praying in gratitude.
She missed on three match points in the eighth game before closing it out.
“When I woke up this morning, the first thing I said was ‘Ouch,’” the 26-year-old Muchova said. “I knew it was going to be a tough task to win, especially against someone like Coco.”
The French Open runner-up will celebrate her birthday on Monday by moving to No. 10 on the WTA rankings.