World number one Novak Djokovic was among those frustrated by rain at the Rogers Cup on the day that saw Andy Murray crash out in Montreal.
Murray's title defence ended with a 6-3 6-1 defeat to Kevin Anderson but rain meant Djokovic's match against Nikolay Davydenko had to be put back to Wednesday.
Rain also led to play being suspended during John Isner's match against Cypriot Marcos Baghdatis, with Isner leading 6-3 0-1.
Plenty of first-round matches were completed though, with 10th-seeded Frenchman Richard Gasquet a resounding 6-3 6-2 winner over Germany's Florian Mayer.
But Gasquet's countryman, ninth seed Gilles Simon, went out to another German. He lost 7-5 6-2 to Phillip Petzschner.
Another seed, number 11 Mikhail Youzhny from Russia, lost 3-6 6-3 7-6 (7-4) to France's Michael Llodra.
Serbia's 12th seed Victor Troicki fell behind against American Michael Yani before pulling off a 2-6 6-3 6-1 victory.
There were also wins for American Michael Russell, Ukraine's Sergiy Stakhovsky, Serbian Janko Tipsarevic and, to the home crowd's delight, Canadian Vasek Pospisil. Their victims, respectively, were Spain's Albert Montanes, German Phillip Kohlschreiber, Colombian Alejandro Falla and Argentinian Juan Ignacio Chela.
