As a professional, Liu has won four singles titles and one doubles title on tournaments of the ITF Circuit. She has reached a career-high 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 the final, in straight sets. 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.[1] With this Grand Slam success, Liu rose to world No. 1 in the girls' junior rankings.
Professional career
She won her first professional title in March 2015, at an Orlando clay-court tournament on the ITF Women's Circuit.[2] At age 14, Liu was the youngest tennis player to win a professional tournament since Anna Kournikova in 1996.[3]
After securing two ITF tournament wins in 2017, Liu was granted again a wildcard 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.[4] 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 at the US Open.[5]
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.[6] Liu was the only player in the tournament to win a set against Kerber.[7]
(W) winner; (F) finalist; (SF) semifinalist; (QF) quarterfinalist; (#R) rounds 4, 3, 2, 1; (RR) round-robin stage; (Q#) qualification round; (P#) preliminary round; (DNQ) did not qualify; (A) absent; (Z#) Davis/Fed Cup Zonal Group (with number indication) or (PO) play-off; (G) gold, (S) silver or (B) bronze Olympic/Paralympic medal; (NMS) not a Masters tournament; (NTI) not a Tier I tournament; (P) postponed; (NH) not held; (SR) strike rate (events won / competed); (W–L) win–loss record.
To avoid confusion and double counting, these charts are updated at the conclusion of a tournament or when the player's participation has ended.