Stephens powers past Muguruza

US Open champion Sloane Stephens upset Spanish third seed Garbine Muguruza 6-3 6-4 yesterday to reach the Miami Open quarter-finals while Czech Karolina Pliskova advanced when her opponent retired hurt.

Stephens, who raised her game to levels similar to last year when she captured a maiden major title in New York, dictated play against the Wimbledon champion from the start.

The American 13th seed raced out of the gate by taking eight of the first nine points of the match. After securing a break in the fifth game of the second set, Stephens sent Muguruza packing with a backhand on the line on her second match point.

Stephens, who equalled her best result in Miami having also reached the quarter-finals in 2015, will next face German 10th seed Angelique Kerber, a 6-7(1) 7-6(5) 6-3 winner over Chinese qualifier Wang Yafan.

Fifth seed Pliskova, who reached last year’s Miami semis, was first to reach the quarters after Zarina Diyas of Kazakhstan was forced to retire injured while trailing 6-2 2-1.