Emil Ruusuvuori defeated Karen Khachanov 7–6, 2–6, 6–2 in the Hong Kong ATP 250 round of 16 on hard court on 3 January 2024, upsetting the pre-match favourite. Khachanov entered as the odds-on favourite at 1.68, but Ruusuvuori's superior performance across the match—particularly his commanding third set—proved decisive. After a closely contested opening set that went to a tiebreak, Ruusuvuori seized control by claiming the second set with a decisive 6–2 scoreline, then maintained momentum in the decider to seal progression. The result represents a significant scalp for Ruusuvuori and marks a notable setback for Khachanov's tournament campaign.