Sinner battles past Borges as tough start to Wimbledon title defence continues

Italian wins 7-6 (4), 7-6 (2), 6-4 in second roundNext faces the unseeded American Jenson BrooksbyJannik Sinner is not making it easy for himself this year. Matches he would have expected to sprint through here have become mini-marathons and there is the small matter of another ­heatwave arriving in London this weekend, which, as we saw in Paris, is his kryptonite.More worrying, as Sinner ­admitted after reaching the last 32 with a 7-6 (4), 7-6 (2), 6-4 victory over the world No 48, Nuno