Simon Greul advanced when Ivan Sergeyev retired 4-0 in the Australian Open qualifying round of 64.
Greul S. advanced when Sergeyev I. retired.
Simon Greul beat Ivan Sergeyev 4-0 after Ivan Sergeyev retired. Umpiry, "Simon Greul vs Ivan Sergeyev — Australian Open Qualifying Round of 64", https://umpiry.com/match/2011-01-14/greul-vs-sergeyev-australian-open-q64?utm_source=cite (as of 14 January 2011).