At 34, Federer still wows himself

Swiss superstar shows no signs of slowing down

Even Roger Federer is impressed by how well he is playing at 34 - and the ease with which he is winning at this US Open.

Federer is into his 10th semifinal at Flushing Meadows and record 38th at all major tournaments. To get back to his first final in New York since 2009, he will have to beat someone he knows quite well: Swiss Olympic and Davis Cup teammate Stan Wawrinka.