been forced to retire injured after going over on her ankle in herfirst round match against aliksandra sasnovich leading 3—1 in the first set, and after receiving treatment tried to play on, but to no avail, much to her obvious anguish. eight—time champion roger federer is through to the second round, but only after his opponent withdrew due to injury. the 39—year—old sixth seed was two sets and a break down when france's adrian mannarino, who was celebrating his 33rd birthday today, slipped and injured his knee. the world number ai battled on and lost the fourth set, then retired after one point in the decider. afterwards, federer explained one of the intricacies of the wimbledon courts and why injuries happen. the grass is more slippery, it's more soft, and as the tournament progresses, he usually gets more harder and easier to move on. but this is obviously terrible that it's back to back matches, and serena, as well, oh my god, i can't believe it. dan evans is through to the second round — and he did well to get his win completed before the rain returned to delay the action on the outside co