Australia's Will Power climbed up to second in the IndyCar championship standings with victory in Toronto on Sunday, his third success in four races.
Pole-sitter Scott Dixon appeared on course to claim victory at the street circuit, only to be hampered by a crash involving Josef Newgarden - the winner in Iowa last time out.
Newgarden hit the wall on lap 59, forcing yellow flags to be brought out seconds after Power and Penske team-mate Helio Castroneves had pitted.
Power capitalised thereafter to win again, with Castroneves taking second and James Hinchcliffe grabbing third on home soil.
Dixon ultimately finished down the field in eighth, one place ahead of championship leader Simon Pagenaud.