MONTREAL, Aug. 5 (UPI) -- Ninth-seeded Kei Nishikori rebounded from a slow start to corral a first-round victory but No. 16 Janko Tipsarevic was an upset victim Monday at the Rogers Cup.
Japan's Nishikori fell in the opening set but rallied for a 4-6, 6-4, 6-2 decision over Canadian Peter Polansky at Stade Uniprix.
Serbia's Tipsarevic, however, wasn't as fortunate, falling in 6-4, 6-3 fashion to Uzbekistan's Denis Istomin.
World No. 1 and reigning two-time champion Novak Djokovic will face Mayer in the second round.