Karina Habsudova defeated Ai Sugiyama 5-7 6-3 7-5 in the US Open round of 64 on hard. The upset overturned the form book — Ai Sugiyama came in leading the head-to-head 2–0, defending last year's round of 64, but Karina Habsudova had been the form player, winning 2 of their last 7 on hard. Karina Habsudova claimed a first win over Ai Sugiyama in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1999-08-30 | US Open | R64 | hard | Ai Sugiyama | 6-2 4-6 7-5 |
| 1998-05-11 | Berlin | R64 | grass | Ai Sugiyama | 6-0 6-2 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.