MONTREAL -- Two-time defending champion Andy Murray is heading home early from the Rogers Cup.
Murray was upset 6-3, 6-1 by Kevin Anderson in the second round in Montreal.
Murray, who had a bye in the first round, was seeded fourth. He's also fourth in the ATP rankings, while his South African opponent is ranked 35th.
Murray, who won the 2009 Rogers Cup in Montreal and defended his title last year in Toronto, said his South African opponent's serve is the best part of his game.
"If he serves well -- it's a very fast court, it's tough to break -- he can be dangerous," Murray said.
The current world No. 1, Novak Djokovic, didn't get a chance to play Tuesday after a steady rain postponed his evening match against Russia's Nikolay Davydenko -- as well as several other scheduled late-afternoon and evening tilts.
The former world No. 1 Federer lost last year's Rogers Cup final to Murray -- but there will be no rematch this year at Montreal's Uniprix Stadium.
"I've always played very well here and today I couldn't get anything going," said Murray, who had 19 unforced errors in the match.
Also, Canada's Vasek Pospisil reached the second round with a 4-6, 6-3, 6-4 win over 22nd-ranked Juan Ignacio Chela of Argentina.
Petzschner will take on Ivo Karlovic of Croatia in the second round.
In other early action, No. 10 seed Richard Gasquet of France got past Florian Mayer of Germany 6-3, 6-2; American qualifier Michael Russell downed Spain's Albert Montanes 7-5, 6-2; Ukraine's Sergiy Stakhovsky upended Germany's Philipp Kohlschreiber 6-2, 7-5; Serbia's Viktor Troicki beat American Michael Yani 2-6, 6-3, 6-1; Michael Llodra of France defeated Mikhail Youzhny of Russia 3-6, 6-3, 7-6; and Janko Tipsarevic of Serbia knocked out Colombia's Alejandro Falla 7-5, 6-1.
A steady downpour in Montreal postponed late-afternoon and evening matches, including several singles matches: Fernando Verdasco of Spain vs. Tobias Kamke of Germany; Marcos Baghdatis of Cyprus vs. American John Isner; Feliciano Lopez of Spain vs. Radek Stepanek of Czech Republic.
All of them are listed on Wednesday's schedule.