Results on the eighth and final day of the ATP Finals at London's O2 Arena on Sunday (x denotes seeding): Doubles Wesley Koolhof/Nikola Mektic (NED/CRO x5) bt Jurgen Melzer/Edouard Roger-Vasselin (AUT/FRA x7) 6-2, 3-6, 10-5 Playing later Singles Dominic Thiem (AUT x3) v Daniil Medvedev (RUS x4) afp