Tetsuya Chaen defeated Danai Udomchoke 6-4 4-6 6-0 in the Japan 1 Masters 1 round of 16 on hard. The upset overturned the form book — Danai Udomchoke came in leading the head-to-head 2–0. Tetsuya Chaen claimed a first win over Danai Udomchoke in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2000-07-24 | Indonesia F4 | R16 | hard | Danai Udomchoke | 6-3 6-0 |
| 1998-11-25 | Japan F6 | R16 | hard | Danai Udomchoke | 7-5 6-2 |
Averages over each player's completed matches in the selected window (1 vs 89). ATP, WTA & Challenger.
Each player's serve crossed against the other's return, converted to expected hold of serve. Recent completed matches, ATP, WTA & Challenger. Small sample — read as indicative. About