Diego Schwartzmann won the annual finals tournament in 2014, but failed to qualify to defend it in 2015, at which sport?
2015 ATP Challenger Tour Finals – Singles Diego Schwartzman was the defending champion, but did not qualify this year.
2015 Stan Wawrinka tennis season The 2015 Stan Wawrinka tennis season began at the Chennai Open, where he won the title for the third time in his career. This was followed by an unsuccessful defense of his title at the Australian Open, where he lost in the semi-finals to eventual champion Novak Djokovic in five sets. A few months later, after a relatively unsuccessful clay season, Stan won his second major title at the French Open, defeating Roger Federer and Novak Djokovic in the process.