When Shapovalov was 13, his training needs were too much for his mother to handle on her own. It was at this point that the family hired Adriano Fuorivia, a former manager of tennis development for Tennis Canada, to be his personal coach and travel with Shapovalov while his parents stayed home to run the academy. The relationship between Shapovalov and Adriano lasted four years, and included numerous junior and ITF futures titles, including the 2015 US Open Junior Doubles title and the 2016 Wimbledon Junior Singles title. In October 2013, Shapovalov won his first junior singles title at the ITF G5 in Burlington, Ontario. He captured his second singles title in April 2014 at the ITF G5 in Burlington. In July 2014, Shapovalov won the singles and doubles titles at the ITF G4 in San José. At the US Open in September 2015, he qualified in singles and made it to the third round for his second straight Grand Slam. In doubles, he won the title with partner Félix Auger-Aliassime. In October 2015, Shapovalov and fellow Canadians Félix Auger-Aliassime and Benjamin Sigouin captured the first Junior Davis Cup title for Canada in its history. At the French Open in May 2016, he advanced to the semifinals in singles and to the second round in doubles. At the beginning of July 2016, he captured his first G1 singles title after winning in Roehampton. A week later, Shapovalov became the third Canadian to win a junior Grand Slam singles title with a three-set victory over Alex De Minaur at the 2016 Wimbledon Championships. He also reached the doubles final with Félix Auger-Aliassime.