BOSTON – Chris Kelly’s newest piece of jewelry is a thick, padlocked chain that he wore around his neck after scoring the winning goal in Boston’s playoff opener Thursday night.

The message: Try not to be the weak link.

“He wasn’t,” Bruins goalie Tim Thomas said after Kelly’s goal on a long slap shot 1:18 into overtime gave the defending Stanley Cup champs a 1-0 victory against the Washington Capitals in Game 1 of their first-round playoff series.

“I had a good feeling that it was going to go in, and I had a good feeling about the guy who had the puck,” said Thomas, the reigning Vezina and Conn Smythe Trophy winner. “I could tell he had something tonight. He’d been winging a few past me in practice the past few days.”

Thomas stopped all 17 shots he faced to earn his sixth career playoff shutout — four of them on Boston’s 2011 championship run. But he was matched for three periods by Capitals goalie Braden Holtby, a third-stringer making his playoff debut because of injuries to Tomas Vokoun and Michal Neuvirth.

Holtby made 29 saves for the Capitals, and he was still perfect when Thomas turned back Marcus Johansson with a toe save that started the Bruins on the break. Brian Rolston dropped it for Benoit Pouliot to clear the zone, and he pushed it up to Kelly.

At the top of the left playoff circle, Kelly uncorked a slapper that sailed over Holtby’s glove for the winner. That earned Kelly the necklace that has taken the place of last year’s good luck charm, a tattered windbreaker that the Bruins handed out to the star of the game during their run to the franchise’s first NHL title since 1972.

“It’s always nice to end it fairly early,” said Kelly, who thought the shot deflected off a defenseman’s stick. “Goalies are so good now, I think the days of going down the wing and beating a goalie are long gone. So I was pleasantly surprised to see it go in.”

Alex Ovechkin of the Capitals consoled Holtby on the ice while the Bruins celebrated their first victory in their quest to become the first repeat Stanley Cup champions since the Detroit Red Wings in 1997-98.