From 3-2 in the first set, Federer ran away with it and not even Nadal’s trademark defensive abilities could handle the pace and accuracy of the 16-time Grand Slam champion’s forehand.

The 26th match between the former No. 1s was over in exactly 1 hour. Federer finished with 28 winners to Nadal’s four.

With one match to play in Group B, Federer is assured of a place in the semifinals as he targets a record sixth title at the season-ending event.

Jo-Wilfried Tsonga earlier kept alive his hopes of reaching the last four by beating Mardy Fish 7-6 (4), 6-1.