01:45TennisUS Open 2017 Quarter-finalsBBC Radio 5 Sports Extra Duration: 5 hours, 15 minutes Thu 7th Sep 2017, 01:45 on BBC Radio 5 Sports ExtraLive quarter-final tennis commentary of the US Open in New York. Including Roger Federer v Juan Martin del Potro.GenresSportTennisSeriesTennis Source: BBC Online