Juan Martin del Potro advanced when Novak Djokovic retired 7-6 3-0 in the SRB vs ARG round robin. Juan Martin del Potro claimed a first win over Novak Djokovic in five meetings, narrowing the head-to-head to 4–1.
del Potro J. advanced when Djokovic N. retired.
del Potro J. and Djokovic N. faced 10 of the same opponents in the last 12 months. del Potro J. went 6–7 (46%) against them, Djokovic N. 17–4 (81%). Djokovic N. came out better against 5 of 9 comparable opponents, del Potro J. against 0.
Hard: Djokovic N. leads 2–1 · Clay: Djokovic N. leads 2–0
Juan Martin del Potro beat Novak Djokovic 7-6 3-0 after Novak Djokovic retired. Umpiry, "Juan Martin del Potro vs Novak Djokovic — SRB vs ARG Round Robin", https://umpiry.com/match/2011-09-16/djokovic-vs-potro-srb-vs-arg-rr?utm_source=cite (as of 16 September 2011).