Barbora Krejcikova defeated Garbine Muguruza 6-3 7-6 in the US Open round of 16 on hard. The upset overturned the form book — Garbine Muguruza came in leading the head-to-head 3–1, defending last year's round of 64, but Barbora Krejcikova had been the form player, winning 7 of their last 10 on hard. Barbora Krejcikova narrowed the head-to-head to 3–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2021-11-12 | Guadalajara | RR | hard | Garbine Muguruza | 2-6 6-3 6-4 |
| 2021-11-10 | Guadalajara Finals | RR | hard | Garbine Muguruza | 2-6 6-3 6-4 |
| 2021-08-19 | Cincinnati | R16 | hard | Barbora Krejcikova | 6-1 6-7(5) 6-2 |
| 2021-03-07 | Dubai | F | hard | Garbine Muguruza | 7-6 6-3 |
Averages over each player's completed matches in the selected window (200 vs 99). ATP, WTA & Challenger.
Performance in the biggest moments — break points, deciding sets and tiebreaks (0–100, higher is better). About
Krejcikova B.: 7 days rest · 1 match, 23 games (7d). Higher means fresher. About
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