Just 2:25 into the first game of the season for both teams, Pavelec collapsed in front of his net and lost consciousness. Pavelec, in his fourth season with the Thrashers, was taken from the ice on a stretcher and rushed to a nearby hospital.
Team officials announced during the game that Pavelec regained consciousness after reaching the hospital and that initial tests were negative. The Thrashers said Pavelec would be kept overnight for observation.
Chris Mason came on to replace Pavelec and gave up a goal to Brooks Laich just 53 seconds after the game resumed.
Kane then scored the first and third of Atlanta's three consecutive goals to put the Thrashers in charge. His second goal came with 1:06 to play in the second period and came on a penalty shot.
The other Atlanta goals came from Andrew Ladd and Fredrik Modin, both of whom played their first game for the Thrashers. Ladd was a member of the Stanley Cup winning Chicago Blackhawks last season and Modin has joined his fifth team in a 14-year career.
Craig Ramsay won in his first game as Atlanta coach. Mason made 29 saves and Washington's Michal Neuvirth stopped 27 shots.
Washington had the best regular-season record in the NHL last year before losing a 3-1 series lead and suffering a first-round playoff elimination at the hands of Montreal. Atlanta finished last in the Eastern Conference.