Sloane Stephens defeated Alison Riske 7-6 6-3 in the Wuhan round of 64 on hard. The upset overturned the form book — Alison Riske came in defending last year's round of 16, but Sloane Stephens had been the form player, winning 3 of their last 7 on hard.
Stephens S. took it in straight sets.
Stephens S. and Riske A. faced 4 of the same opponents in the last 12 months. Stephens S. went 1–3 (25%) against them, Riske A. 0–4 (0%). Results against comparable opponents are close (1 : 0 better-results split).
Only 4 common opponents — small sample, treat as indicative.
Sloane Stephens beat Alison Riske 7-6(4) 6-3. Umpiry, "Sloane Stephens vs Alison Riske — Wuhan Round of 64", https://umpiry.com/match/2015-09-28/riske-vs-stephens-wuhan-r64?utm_source=cite (as of 28 September 2015).