Yasufumi Yamamoto defeated Tetsuya Chaen 6-4 6-2 in the Japan 1 Masters 4 round of 32 on hard. The upset overturned the form book — Tetsuya Chaen came in leading the head-to-head 2–0. Yasufumi Yamamoto claimed a first win over Tetsuya Chaen in three meetings, narrowing the head-to-head to 2–1.
Yamamoto Y. took it in straight sets.
Yasufumi Yamamoto beat Tetsuya Chaen 6-4 6-2. Umpiry, "Yasufumi Yamamoto vs Tetsuya Chaen — Japan 1 Masters 4 Round of 32", https://umpiry.com/match/1999-06-07/chaen-vs-yamamoto-japan-1-masters-4-r32?utm_source=cite (as of 7 June 1999).