Chan Yeong Oh defeated Issei Okamura 6-1 4-6 10-7 in the M25 Daegu 1 qualifying round of 32 on hard. The upset overturned the form book — Issei Okamura came in leading the head-to-head 1–0, but Chan Yeong Oh had been the form player, winning 4 of their last 9 on hard. Chan Yeong Oh claimed a first win over Issei Okamura in two meetings, levelling the head-to-head at 1–1.
Yeong Oh C. came through in three sets.
Chan Yeong Oh beat Issei Okamura 6-1 4-6 10-7. Umpiry, "Chan Yeong Oh vs Issei Okamura — M25 Daegu 1 Qualifying Round of 32", https://umpiry.com/match/2023-06-05/oh-vs-okamura-m25-daegu-1-q32?utm_source=cite (as of 5 June 2023).