Federer beats Wawrinka in thriller to set up dream final

Roger Federer of Switzerland reacts during his semi-final tennis match against Stan Wawrinka of Switzerland at the ATP World Tour Finals at the O2 Arena in London November 15, 2014. REUTERS/Toby Melville

LONDON (Reuters) - Roger Federer saved four match points before winning a gripping semi-final in a deciding set tiebreak against fellow Swiss Stanislas Wawrinka on Saturday to set up a dream ATP World Tour Final climax with Novak Djokovic.

Six-times champion Federer survived a nerve-shredding battle before emerging victorious 4-6 7-5 7-6(6) in the standout match of the week at London's O2 Arena, although Wawrinka should have prevailed.