Ai Sugiyama (杉山愛, Sugiyama Ai; born July 5, 1975) is a Japanese former tennis player. She reached the world No. 1 ranking in women's doubles on the WTA Tour and had a career-high singles ranking of world No. 8, achieved on February 9, 2004. In her career, she won six singles and 38 doubles titles, including three major titles (one with Julie Halard-Decugis and two partnering Kim Clijsters), and one mixed doubles title (partnering Mahesh Bhupathi). Sugiyama held the all-time record, for both male and female players, for her 62 consecutive Grand Slam tournament main-draw appearances, until she was surpassed by Roger Federer at the 2015 Wimbledon Championships.
In 1993, at age 17, Sugiyama played tennis legend Martina Navratilova in her native city, losing in three sets. The same year, she made her Grand Slam debut at Wimbledon but lost in the first round to world No. 30, Gigi Fernández, in three sets. In 1994, Sugiyama again reached the main draw at Wimbledon but lost to world No. 6 and compatriot, Kimiko Date. Later that year, she reached her first singles final in Surabaya but was forced to retire against Elena Wagner. She went on to win the Japan Open doubles, her first tour title. Later that year, she broke into the WTA top 100. In 1995, she won her first Grand Slam match and reached the fourth round of Roland Garros. In the first round, the Japanese player defeated 15th-seeded Grand Slam runner-up and former top-5 player Helena Suková by 9–7 in the final set, her first victory over a top-20 player. Two months after, she defeated Amanda Coetzer to reach the third round, while losing to world No. 4 and former Wimbledon champion, Conchita Martínez. In November, she made an impressive run at the Oakland Tier-II tournament. While she was only ranked 63, she defeated 22nd-ranked Irina Spîrlea, former Wimbledon runner-up Zina Garrison Jackson, and No. 10, Lindsay Davenport to reach the second final of her career, where she lost to No. 7, Magdalena Maleeva. After this run, Sugiyama broke into the top 50.
In 1996, she reached the third round at the Australian Open. In Miami, seeded 23rd, Sugiyama reached the fourth round, defeating No. 10, Jana Novotná, her second top-10 victory. That moved her into the top 30. She also reached the semifinals of the Japan Open in Tokyo and the fourth round at Wimbledon, where she defeated No. 5, Anke Huber, her third top-10 and first top-5 victory. She represented Japan and reached the third round at the Atlanta Olympics, defeating Martina Hingis.
Sugiyama began 1997 season by playing her third final losing to Elena Likhovtseva, after defeating Sabine Appelmans in the quarterfinals. The following week she reached the second round at the Australian Open. In April, she won her first professional title at the Japan Open against Amy Frazier. However, she could not reach a good result in Grand Slam events, with a second-round exit at the French Open and US Open and a first round loss at Wimbledon. At the end of the year, she reached her first Tier-I final at the Kremlin Cup in Moscow, defeating Natasha Zvereva, No. 14 Brenda Schultz-McCarthy, No. 9 and multi-Grand Slam events winner Arantxa Sánchez Vicario, and Dominique Van Roost before failing in the final against top seed and second-ranked Jana Novotná.
In 1998, she opened with a second singles title in Gold Coast. Then she broke into the top 20 and reached another semifinal in Sydney, defeating Conchita Martínez. Throughout that year, Sugiyama showed consistency: a third WTA Tour title at the Japan Open, quarterfinals in Tokyo (Pan Pacific), Berlin, defeating No. 4, Amanda Coetzer, playing Strasbourg and San Diego, defeating Steffi Graf, Luxembourg, third round in Indian Wells, Miami and Montreal and second round at both French and US Open. In 1999, she reached the final of the Japan Open, the semifinals in Gold Coast and Tokyo (Princess Cup) defeating No. 8, Julie Halard-Decugis, the quarterfinals in Strasbourg and Moscow, defeating No. 6, Mary Pierce, third in Indian Wells, Montreal, defeating No. 7, Jana Novotná, and at the US Open. She also reached the second round at the French Open and Wimbledon. The same year, Sugiyama won the US Open mixed doubles with Mahesh Bhupathi, her first Grand Slam title.
Sugiyama received the WTA Sportsmanship Award in 1999.
Sugiyama reached the final of the women's doubles at Wimbledon, partnered by Halard-Decugis, but lost on July 10 in straight sets to the Williams sisters after a one-day rain delay. On September 10, she won the women's doubles at the US Open, defeating Cara Black and Elena Likhovtseva in three sets, in one hour and 19 minutes. On October 23, she became the first Japanese woman to rank world No. 1 in doubles, winning seven titles in the process.
Her greatest success was Scottsdale 2003. Beating Lindsay Davenport in the second round, she went on to defeat Eleni Daniilidou to progress to the semifinals. Scheduling problems forced both the semifinals and finals matches - for both singles and doubles - to be played on the Sunday of the tournament. Thus in a single day, Sugiyama managed to save a matchpoint in the semifinals against Alexandra Stevenson, rally from a set down to defeat doubles partner Kim Clijsters in the final, and then secure victories in both doubles matches to raise both trophies. The year 2003 proved to be her best year ever, pushing Serena Williams to the limit at Roland Garros and reaching the round of 16 in Wimbledon and US Open where her fourth round loss to Francesca Schiavone at Flushing Meadows was rather controversial. She finished the year ranked tenth, having defeated world No. 1, Justine Henin, in the round robin section of the season-ending championships. She also won a total of eight doubles titles that year, seven with Kim Clijsters (Sydney, Antwerp, Scottsdale, Roland Garros, Wimbledon, San Diego, Zurich) and one with Liezel Huber (Linz).
Sugiyama began 2005 with four consecutive first-round losses. She lost in the first rounds of the first three majors; only at San Diego did she really do well, making it to the final, which she lost in straight sets to Mary Pierce, having defeated Daniela Hantuchová, Sesil Karantacheva and Svetlana Kuznetsova en route. Sugiyama also reached the final in doubles with Hantuchová, losing to Virginia Ruano-Pascual and Conchita Martínez. She broke her Grand Slam tournament "curse", reaching the third round before losing to Clijsters, the eventual champion.
That year, Ai had better results in doubles than in singles. Partnering with Elena Dementieva, she reached the finals of her first tournament, Sydney, losing to Bryanne Stewart and Samantha Stosur. They reached the round of 16 at the Australian Open. She entered a few tournaments with Anastasia Myskina and Elena Likhovtseva, but with poor results. In Berlin, she played again with Daniela Hantuchová, reaching the semifinal, losing to Black and Huber. At the French, they lost to Birnerová and Vanc in the second round. They won their next tournament, in Birmingham over Daniilidou and Russel. At Wimbledon, Hantuchová and Sugiyama reached the quarterfinal, losing to eventual champions Black and Huber. At the Canadian Open in Toronto, they lost the semifinal to eventual champions Grönefeld and Navratilova. At the US Open, they reached the third round, losing to Yan Zi and Zheng Jie. She tried three partners in the next tournaments, before returning to Daniela in Zurich, where they reached the finals (beating top seeds Lisa Raymond and Stosur en route), losing a close three-set match to Black and Rennae Stubbs. They finished the year ranked No. 5, failing to qualify for the year-end championships.
Sugiyama played mixed doubles at two events: the French & the US Open. At Roland Garros, playing with Mirnyi, she lost in the first round. At the US Open, she partnered with Ullyett. The duo reached the quarterfinals, losing to eventual champions Hantuchová and Bhupathi. Entering the Doha with an 0–5 singles record, she managed to beat wildcard Selima Sfar. In the second round, she upset Myskina in three sets, needing several match points to close the match out. In her quarterfinal match against Julia Schruff, she had a comfortable win. She lost in the semifinal, in an epic match against Nadia Petrova. At 0–4 in the second, she won five consecutive games to 5–4. She won the doubles title with Hantuchová, defeating Yan and Zheng in the semifinal and Li Ting and Sun Tiantian in the final.