Keys, who reached the US Open final in 2017, displayed exceptional discipline on the Arthur Ashe Stadium court, securing a convincing 6-1, 6-4 victory in just 1 hour and 26 minutes.
The 17th-seeded American will now face off against the second-seeded Aryna Sabalenka of Belarus on Thursday for a chance to advance to the final.
Marketa Vondrousova, the Czech ninth seed who made history by becoming the first unseeded woman to win Wimbledon in July, must have been disappointed as she couldn’t capitalize on any of the nine break points she had against Keys. In contrast, Keys capitalized on all three break points she encountered, earning her sixth appearance in the semi-finals of a Grand Slam.
Keys credited the home support for helping her navigate through Vondrousova’s nine break point opportunities.
“I love playing here, in front of a home crowd — you never feel like you can’t get out of any situation,” Keys said.
The American said she had decided beforehand to go on the front foot against Vondrousova.
“Just being able to stay aggressive and staying on the front foot the whole time,” Keys said, who was beaten by semi-final opponent Sabalenka in straight sets when the two met in the quarter-finals at Wimbledon in July.
“It’s going to be a lot of hard-hitting, not a lot of long points,” Keys said of Thursday’s semi-final.
“I’m just going to buckle up and get as many balls back as I can.”
(With inputs from AFP)