Canadian teenager Victoria Mboko completed a dream run to the National Bank Open title Thursday night, overcoming a slow and swollen right wrist start to beat Japanese star Naomi Osaka 2-6, 6-4, 6-1.

Victoria Mboko didn’t even have a picture on the Women’s Tennis Association (WTA) website before the Canadian Open in Montreal. Now, the 18-year-old has defeated four-time grand slam champion Naomi Osaka in the first WTA Tour final of her career.

Osaka joined Mboko in pulling out of the main tuneup for the U.S. Open after their gripping contest in Montreal.