Stan Wawrinka defeated Donald Young 6-4 1-6 6-3 6-4 in the US Open round of 16 on hard. The upset overturned the form book — Donald Young came in leading the head-to-head 1–0, defending last year's round of 128. Stan Wawrinka claimed a first win over Donald Young in two meetings, levelling the head-to-head at 1–1.
Wawrinka S. came through in four sets.
Wawrinka S. and Young D. faced 3 of the same opponents in the last 12 months. Wawrinka S. went 3–1 (75%) against them, Young D. 1–2 (33%). Results against comparable opponents are close (2 : 1 better-results split).
Only 3 common opponents — small sample, treat as indicative.
Stan Wawrinka beat Donald Young 6-4 1-6 6-3 6-4. Umpiry, "Stan Wawrinka vs Donald Young — US Open Round of 16", https://umpiry.com/match/2015-09-07/wawrinka-vs-young-us-open-r16?utm_source=cite (as of 7 September 2015).