Kei Nishikori defeated Jack Sock 7-5 6-2 in the Washington round of 32 on hard. The upset overturned the form book — Jack Sock came in leading the head-to-head 2–0, but Kei Nishikori had been the form player, winning 3 of their last 6 on hard. Kei Nishikori claimed a first win over Jack Sock in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2017-03-06 | Indian Wells Masters | QF | hard | Jack Sock | 6-3 2-6 6-2 |
| 2014-10-05 | Shanghai Masters | R32 | hard | Jack Sock | 7-6(5) 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
Averages over each player's completed matches in the selected window (200 vs 199). ATP, WTA & Challenger.
Performance in the biggest moments — break points, deciding sets and tiebreaks (0–100, higher is better). About