
Reilly Opelka defeated Soon Woo Kwon 6-3 6-4 in the Delray Beach quarter-final on hard. The result followed the form book — Reilly Opelka came in leading the head-to-head 1–0, defending last year's round of 16. Reilly Opelka extended the head-to-head to 2–0.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2021-08-30 | US Open | R128 | hard | Reilly Opelka | 7-6(3) 6-4 6-4 |
Each player's serve crossed against the other's return, converted to expected hold of serve. Recent completed matches, ATP, WTA & Challenger. About
Per-surface Serve / Return Rating (0–100, percentile within the hard field, opponent-adjusted over 52 weeks). About
Averages over each player's completed matches in the selected window (190 vs 173). ATP, WTA & Challenger.