Buyunchaokete split two tiebreaks before taking the deciding set 6–2 against eighth seed Kamil Majchrzak in Hangzhou on September 26, 2026. The 7–6(4), 6–7(5), 6–2 victory put him into the quarter-finals.
He had arrived at the tournament with one tour-level win in the 2026 season. This result gave him two wins in Hangzhou alone, exceeding his total from the preceding part of the season.
Coleman Wong also won in three sets, beating fifth seed Adolfo Daniel Vallejo 7–6(2), 4–6, 6–3. Wong followed a won opening tiebreak and a lost second set with a successful decider to set up a quarter-final against Daniil Medvedev.
Roman Safiullin came from a set down to beat fourth seed Quentin Halys 5–7, 6–3, 6–4. Their first tour meeting lasted two hours and 17 minutes and set up a Safiullin–Buyunchaokete quarter-final.
