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 at Tokyo, 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. Because of this, Sugiyama broke into the top 50.