Tim Thomas prevailed in a goaltending showdown and his shutout gave the Boston Bruins a 1-0 overtime triumph over the Washington Capitals in the opening match in their first-round playoff series on Thursday.

Boston's Chris Kelly fired a slap shot past unproven Washington goaltender Braden Holtby for the game-winner just 1:18 into overtime to give the defending Stanley Cup champions a 1-0 series lead.

"I never thought it was going to be an easy game, I could tell that Holtby was on right away," Thomas told reporters after finishing with 17 saves to Holtby's 29.

"I was just trying to make sure to stay on my toes, when you don't have that many shots it can be difficult."

In New York, the Rangers played like the top seeds they are in a convincing 4-2 victory over the Ottawa Senators to take a the 1-0 edge in their best-of-seven series.

Having won the Eastern Conference for the first time since their 1994 Stanley Cup triumph, the Rangers looked ready to go all the way this year as they raced to a 4-0 lead and got 30 saves from Henrik Lundqvist.

In Boston, Thomas faced just seven shots in about the first 40 minutes but his offense just could not break through.

Holtby, forced into action because of injuries to Washington's regular goaltenders, played just seven games during the regular season but shone in his understudy role.

(Writing by Jahmal Corner in Los Angeles; editing by Nick Mulvenney)