Elena Rybakina off the mark in Cincinnati

The world number 25 set up a second-round clash with eighth seed Garbine Muguruza, title-winner here in 2017. Rybakina's success rate since defeating Ons Jabeur in the All England Club final has been modest, with a first-round defeat at the Silicon Valley event and a 1-1 record last week in Toronto.

The 23-year-old Kazakh lifted her game in the second set to end with five aces and 13 winners against Sharif. "I was slow at the beginning but I got my rhythm and served well," Rybakina said.

"But my serve always helps me." The newest Grand Slam champion said she is trying to look ahead in her career as she adjusts to her status. "Wimbledon gave me confidence but now I'm focusing on my other tournaments and trying not to think of the past," she said.