Wimbledon day four: Upsets of the day

Wimbledon title favourite Karolina Pliskova crashed to a shock second round defeat against world number 108 Magdalena Rybarikova on Thursday. Rybarikova battled back from a set down to win 3-6, 7-5, 6-2 on Centre Court, earning the Slovakian a last 32 clash with Ukraine's Lesia Tsurenko. Photo: Getty
Ernests Gulbis sprang a Wimbledon surprise as the World No. 589 defeated former U.S. Open champion Juan Martin Del Potro 6-4, 6-4, 7-6 (7/3) on Thursday. Gulbis will face three-time champion Novak Djokovic in the third round after scoring his best result in three years. Photo: Getty
In a marathon contest that nearly went on for four hours, 32-year-old Dudi Sela came back from a set down twice, to stun giant American John Isner 6-7 (5/7), 7-6 (7/5), 5-7, 7-6 (7/5), 6-3. Isner has never been past the third round at Wimbledon, where he won the longest match in tennis history in 2010, 70—68 in the fifth set. Photo: Getty
Twelfth seeded Kristina Mladenovic squandered her opening set lead to suffer a 2-6 6-4 6-4 to 46th ranked American Alison Riske. Photo: Getty
Leander Paes’ 23rd appearance at Wimbledon was cut short with a first round defeat against Julian Knowle and Philipp Oswald. Paes and Adil Shamasdin lost 6—4 6—4 2—6 6—7(2) 8—10 in a thrilling five-set encounter that was just short of four hours. Photo: AFP