It's been a rough go for Victoria Mboko since her triumph at home.
The Canadian teen sensation dropped her fourth straight match on Tuesday, falling in straight sets to Ukraine's Dayana Yastremska 6-3, 7-6 (3) at the Ningbo Open in China.
Mboko has yet to win a single set since her victory over Naomi Osaka in the final of the National Bank Open presented by Rogers in Montreal.
The 19-year-old's latest defeat came with some struggles on the serve, as she failed to make an ace while committing seven double-faults against Yastremska. Mboko also surrendered six of 14 break-point opportunities, though she converted on five of nine herself.
Since her win in Canada, Mboko, of Burlington, Ont., has also lost first-round matches at the US Open, China Open and Wuhan Open.
She sits 22nd in the live WTA rankings after her latest defeat.
