The 18-year-old Gauff was presented with a special gift by the tournament after clinching the No. 1 doubles ranking.

Eighteen-year-old Coco Gauff has become the 46th No. 1 in WTA doubles rankings history after capturing the WTA 1000 title in Toronto alongside Jessica Pegula.

The all-American duo defeated American-Australian pair Nicole Melichar-Martinez and Ellen Perez in a match tie-break in the final on Sunday, 6-4, 6-7 (5), 10-5.

"Oh my god, No. 1 in something!" Gauff said to Pegula at their bench after the match.

Over the last 12 months Gauff has won two WTA 1000 titles—both with Pegula and both this year, at Doha and now Toronto—and has reached her first two Grand Slam doubles finals, at the US Open last year with Caty McNally and at Roland Garros this year with Pegula. She also reached the Stuttgart final this year with China's Zhang Shuai.

Gauff jumped five spots from No. 6 to No. 1, soaring past her previous career-high of No. 5, which she set after the aforementioned Roland Garros final in June.

The 18-year-old is now the second-youngest woman to top the WTA doubles rankings since they began in 1984, after Switzerland's Martina Hingis, who was still 17 years old when she first ascended to the top spot on June 8th, 1998.