Ukrainian fifth seed Elina Svitolina delivered a solid serving performance to beat American Madison Keys 7-5 6-4 on Sunday and secure a spot in the U.S. Open quarter-finals.
Keys, who finished runnerup in 2017, struggled with her backhand and Svitolina won 92 per cent of her first serve points.
She also did not face a single break point during the 75-minute clash under the Arthur Ashe Stadium lights.
With the win, Svitolina is the first Ukrainian woman to reach the U.S. Open quarter-finals since Kateryna Bondarenko in 2009.
Up next for Svitolina will be Briton Johanna Konta, who upset Czech third seed Karolina Pliskova earlier on Sunday.