Alexander Zverev moved into the quarter-finals of the US Open with a straightforward 6-2, 6-2, 6-1 win over Spain's Alejandro Davidovich Fokina. The 21-year-old had beaten Cameron Norrie of Great Britain in the previous round, and had dispatched 24th seed Hubert Hurkacz in round two. But he had no answer for the fifth seed, who hit 18 aces and took seven of his ten break point chances – hitting 38 winners compared to his opponent's 17. The world number seven clocked his fastest serve of the match at 139 mph, just shy of his personal record of 142 mph. "IвЂ™m in the quarter-finals and that can only be a good thing," said Zverev, who reached the Australian Open semi-finals earlier this year. Davidovich was moving very poorly by the end of the match, suffering with what appeared to be a troublesome Achilles.