Resurgent Federer books ATP World Tour Finals berth

Aug 17, 2014; Cincinnati, OH, USA; Roger Federer returns a shot from David Ferrer on day seven of the Western and Southern Open tennis tournament at Linder Family Tennis Center. Mandatory Credit: Mark Zerof-USA TODAY Sports

LONDON (Reuters) - A resurgent Roger Federer has qualified for a record 13th consecutive ATP World Tour Finals in comfortable fashion, in marked contrast to 2013 when he squeezed in the week before the end-of-season tournament in London.

Federer, 33, claimed his sixth Western and Southern Open title in Cincinnati on Sunday with victory over Spain's David Ferrer, the last key tune-up event for the U.S. Open.