Tennis players often say it’s hard to play against a friend, the killer instinct never quite as easy to call on as it might be against someone else. Aryna Sabalenka, the world No 1, has rarely had that problem, but she was pushed hard by her former doubles partner Elise Mertens before winning through 6-4, 7-6 (4) to reach the quarter-finals.
Mertens had won just two sets in their past nine matches but played as good a match as she has ever done at Wimbledon, and still came out on the wrong side. Sabalenka hit 36 winners and made just 18 unforced errors, coming from 3-1 down in the second set to set up a quarter-final against Laura Siegemund of Germany.
