NEW YORK: Venus Williams battled bravely before bowing out of the US Open on her return to Grand Slam tennis on Monday as Melbourne champion Madison Keys suffered a shock first-round exit.
The second full day of action in New York saw all eyes turn to the Arthur Ashe Stadium's night session, where the 45-year-old Williams lost in three sets to 11th seed Karolina Muchova.
Williams only returned to competitive tennis in July following a 16-month absence from the sport and had been granted a wild card into the main draw at Flushing Meadows.
But hopes of a fairytale run -- 28 years after her debut in the tournament in 1997 -- ended in a 6-3, 2-6, 6-1 loss to Muchova, who was not even born when Williams turned professional in 1994. "I didn't win today but I'm very proud of the way I played," Williams said.
"I don't think I've ever had a crowd on my side like that. I knew people around the world and around the United States were really rooting for me, and that felt great," she added.
Also on Monday, Australian Open winner Keys became the highest-ranked player to exit so far, the sixth seed losing to Mexico's Renata Zarazua 6-7 (10/12), 7-6 (7/3), 7-5.
"Today was the first time in a while where my nerves really got the better of me and it kind of became a little bit paralyzing," home hope Keys said.
"I was just slow, I wasn't seeing things the way that I wanted to, which I feel like resulted in a lot of bad decisions and lazy footwork."
Kvitova farewell
Czech Republic's Barbora Krejcikova bundled out rising Canadian star Victoria Mboko, defeating the teenager 6-3, 6-2.
Belgian 19th seed Elise Mertens ousted wild card Alyssa Ahn 6-1, 6-0 while Ukrainian 30th seed Dayana Yastremska exited in a 6-7 (5/7), 7-6 (7/5), 6-4 loss to Russia's Anastasia Pavlyuchenkova.
Two-time Wimbledon champion Petra Kvitova formally brought the curtain down on her career after a 6-1, 6-0 defeat to France's Diane Parry.
The 35-year-old Czech had already announced her intention to retire after the US Open, but was nonetheless overcome with emotion as she said farewell to the sport, breaking down in tears as she addressed fans afterwards.
"I hoped I would put on a better show today," Kvitova said. "It was tough to know it could be my last match, and emotionally it was very tough as well."
In the men's draw, qualifier Coleman Wong scored a notable win, becoming the first player from Hong Kong to record a victory in a Grand Slam singles event in the Open era with a 6-4, 7-5, 7-6 (7/4) defeat of US player Aleksandar Kovacevic.
It was the latest in a series of breakthrough results by young Asian players at this year's US Open.
Alexandra Eala of the Philippines -- who trains with Wong at Rafael Nadal's academy in Spain -- and Indonesia's Janice Tjen both won their first round games in the main draw.
British fifth seed Jack Draper needed four sets to get past Argentina's Federico Gomez, 6-4, 7-5, 6-7 (7/9), 6-2.
Other seeds to advance included Norway's Casper Ruud, the 12th seed, who downed Austria's Sebastian Ofner 6-1, 6-2, 7-6 (7/5).
US 17th seed Frances Tiafoe beat Japan's Yoshihito Nishioka 6-3, 7-6 (8/6), 6-3.