Marin Čilić (Croatian pronunciation: ; born 28 September 1988) is a Croatian professional tennis player whose biggest success to date is having won the 2014 US Open. Over the course of his career, Čilić has won 16 ATP singles titles. His career-high singles ranking is world No. 6, achieved in November 2016. Čilić first came to international prominence by defeating then World No. 2 Andy Murray in the fourth round of the 2009 US Open. He followed this by reaching the semifinals of the 2010 Australian Open. Čilić was also a quarterfinalist at the 2014 and 2015 Wimbledon Championships and a semifinalist at the 2015 US Open as defending champion.