It already was going to be an all-American women’s final at the U.S. Open. Madison Keys made sure she was one of them.

With what likely was the finest performance of her Grand Slam career, Keys put away CoCo Vandeweghe, 6-1, 6-2, in a little under an hour on Thursday night. The match time will say an hour and six minutes, but that includes seven minutes for Keys to get her right hamstring taped. She took a crowd-worrying medical timeout after the fifth game of the second set.

“I definitely started to feel it,” Keys said. “I was scared if I let it go. Just needed to make sure I was OK.”

The first set was a blowout. When Vandeweghe put away a short ball on Keys’ serve in the fifth game, it was only the fourth point she had won in the set. She was facing 15-foot seas in a canoe. Keys won 62 points, Vandeweghe 36. Keys won 22 of 30 first serves and a whopping 13 of 17 second serves.

“It still doesn’t feel real. I’m still shaking,” Keys said. “Lot of things in my head right now and struggling to come up with words.”

Things were not looking good for Keys at the end of last season and the first part of 2017. She underwent surgery on her left wrist in November and came back in March, winning four matches in six tournaments through the French Open. The wrist still hurt, and after it was discovered that there were complications from the first surgery, she underwent a second one, coming back at Wimbledon.

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Keys won the small hardcourt tournament at Stanford in July, beating Vandeweghe in the final. She beat her again in the first round at Cincinnati.

Vandeweghe had been waiting for something good to happen at her home Grand Slam, where she was the junior girls champion at age 16 in 2008. But before this year, she had won a total of only four matches at Flushing Meadows.

This has been her best Grand Slam season by far, reaching the semis at Australia and the quarterfinals at Wimbledon. A coaching change, bringing aboard intense Aussie Pat Cash, has produced a better sense of focus and a channeling of her intensity.

Under the tutelage of Grand Slam winner Lindsay Davenport, the 22-year-old Keys has blossomed. Now she gets to play long-time rival and friend Sloane Stephens in Saturday’s final, the first Grand Slam final for both players.

“Sloane is a new person right now,” Keys said. “She’s loving being on the court again. I’m pretty excited we get to play in the U.S. Open final.”