Nick Kyrgios
In his junior career, Kyrgios won the boys' singles event at the 2013 Australian Open and the boys' doubles event at the 2013 Wimbledon Championships. During his professional career, he reached the quarterfinals of the 2014 Wimbledon Championships and the quarterfinals of the 2015 Australian Open. He is only the third player, after Dominik Hrbaty and fellow Australian Lleyton Hewitt, to have beaten Roger Federer, Rafael Nadal and Novak Djokovic the first time he played each of them.