Claire Liu
Claire Liu is an American tennis player.
In 2017, she was the world No. 1 in the junior rankings after winning the Wimbledon girls' singles title, and finishing runner-up at the French Open. Liu also won a junior Grand Slam doubles title at Wimbledon with Usue Arconada in 2016.
On the pro circuit, Liu has won four ITF singles titles and one doubles title. She reached a career-high WTA singles ranking of world No. 137.
Junior career
Liu won the Junior Wimbledon doubles tournament in 2016 with fellow American Usue Arconada, defeating Mariam Bolkvadze and Caty McNally in straight sets in the final. The following year after losing in the Junior French Open final to Whitney Osuigwe, she came back to win the Wimbledon singles title against Ann Li, making her the first American girl to win the event since Chanda Rubin in 1992. With this Grand Slam success, Liu rose to No. 1 in the ITF girls' junior rankings.Professional career
She won her first professional title on March 22, 2015, at an Orlando clay-court tournament on the ITF Women's Circuit. At age 14, Liu was the youngest tennis player to win a professional tournament since Anna Kournikova in 1996.At the 2015 US Open, Liu was granted a wild card into the qualifying tournament. She beat Verónica Cepede Royg and ninth seed Jana Čepelová in her first two matches before losing to the 26th seed, Alexandra Panova, in the final round. Liu, alongside Taylor Fritz, was also given a wild card for the mixed doubles event; they were defeated in the first round by the fourth seeds and eventual champions, Martina Hingis and Leander Paes.
After securing two ITF tournament wins in 2017, Liu was granted a wild card into the qualifying for the US Open. She defeated all three of her opponents in the qualifying tournament, earning her a spot in the singles main draw of a Grand Slam championship for the first time. There she was defeated in the first round, in straight sets by Duan Yingying. In their Grand Slam doubles main-draw debut, Liu and Taylor Johnson lost in the first round in Women's Doubles at the US Open.
At the 2018 Wimbledon Championships, Liu advanced to the main draw by winning all of her qualifying matches. She lost in the second round to the eventual champion Angelique Kerber. Liu was the only player in the tournament to win a set against Kerber.
Grand Slam performance timelines
Singles
| Tournament | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | SR | W–L | Win% |
| Australian Open | A | A | A | A | Q1 | A | 0 / 0 | 0–0 | |
| French Open | A | A | A | Q2 | Q1 | 0 / 0 | 0–0 | ||
| Wimbledon | A | A | A | 2R | Q1 | NH | 0 / 1 | 1–1 | |
| US Open | Q3 | A | 1R | 2R | A | 0 / 2 | 1–2 | ||
| Win–Loss | 0–0 | 0–0 | 0–1 | 2–2 | 0–0 | 0–0 | 2–3 | 0–0 |
ITF Circuit finals
Singles: 6 (4 titles, 2 runner–ups)
| Result | W–L | Date | Tournament | Tier | Surface | Opponent | Score |
| Win | 1–0 | Mar 2015 | ITF Orlando, United States | 10,000 | Clay |  Fanny Stollár | 6–1, 6–3 |
| Win | 2–0 | May 2017 | ITF Naples, United States | 25,000 | Clay |  Danielle Collins | 6–3, 6–1 |
| Win | 3–0 | May 2017 | ITF Caserta, Italy | 25,000 | Clay |  Paula Badosa | 6–3, 6–3 |
| Win | 4–0 | Oct 2019 | ITF Florence, United States | 25,000 | Clay | Peyton Stearns | 6–1, 6–2 |
| Loss | 4–1 | Jan 2020 | ITF Malibu, United States | 25,000 | Hard |  Nadia Podoroska | 6–3, 3–6, 3–6 |
| Loss | 4–2 | Feb 2020 | ITF Nicholasville, United States | 100,000 | Hard |  Olga Govortsova | 4–6, 4–6 |