The Arthur Ashe Stadium crowd roared.

Madison Keys let out a yell full of joy.

Her throwback U.S. Open performance continued Wednesday night.

The 17th-ranked American is back in the semifinals in Flushing after a five-year hiatus, and she’s gotten there in impressive fashion, dropping just one set so far.

Keys had little trouble with ninth-seeded Czech Marketa Vondrousova, cruising to a 6-1, 6-4 victory. 

With the win, Keys advanced to the semifinals for the third time at the US Open, and for the sixth time at a grand slam.

She has never won a major tournament.

Keys will face No. 2 Aryna Sabalenka in the semifinals on Friday, the only player who has been more dominant on the women’s side in the tournament. 

Keys was dominant in the first set, which took just 39 minutes.

The eight-minute delay, due to a fan needing medical assistance near the court, didn’t bother her.

The match was stopped at deuce in the first game.

Keys responded by ripping off the next eight points and 12 of the following 13 to gain control of the opening set.

Twice, she broke Vondrousova and ended three games with forehand winners, including the final point of the set. 

The forehand helped Keys control the match.

When she faced two break points late in the second set on serve, she went to the forehand to bail her out.

Ultimately, down 4-3, Keys saved four break points and then broke Vondrousova in the ensuing game to enabled her to serve out the match.