LONDON, Nov. 16 (Xinhua) -- Following are the results on the sixth day of the ATP Finals at London's O2 Arena on Friday:

Singles

Guga Kuerten Group

3-Alexander Zverev, Germany, bt 8-John Isner, United States, 7-6 (5), 6-3

1-Novak Djokovic, Serbia, bt 5-Marin Cilic, Croatia, 7-6 (7), 6-2

Doubles

Knowles/Nestor Group

3-Lukasz Kubot, Poland/Marcelo Melo, Brazil, bt 1-Oliver Marach, Austria/Mate Pavic, Croatia, 7-6 (4), 6-4

8-Pierre-Hugues Herbert/Nicolas Mahut, France, bt 5-Mike Bryan/Jack Sock, United States, 6-2, 6-2

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