BOSTON – Brad Marchand turned the emotion of Boston’s banner-raising ceremony into an early goal. Then, suddenly, the momentum was all Philadelphia’s.

Claude Giroux and Jakub Voracek scored 47 seconds apart in the final minute of the first period to give the Flyers the lead, and they held on for a 2-1 victory Thursday night to spoil the Bruins’ celebration of their Stanley Cup championship.

Ilya Bryzgalov made 22 saves in his first game for the Flyers, and Jaromir Jagr recorded his 1,600th NHL point in his first game back in the league after three years in Russia.

“We played the Stanley Cup champions. It’s not easy,” said Jagr, one of eight new players for Philadelphia, including three rookies. “They’re probably the best team in the NHL and we’ve got totally a new team. A lot of young guys. A lot of rookies. You’ve got to give us time.”

Marchand scored midway through the first period for Boston, and reigning Vezina and Conn Smythe winner Tim Thomas stopped 27 shots on the night the 2011 Bruins shared the stage with Bobby Orr and a handful of others from the 1972 Stanley Cup champions.

During a half-hour pregame ceremony the Bruins, who clinched the Cup in Vancouver, took the opportunity to pass the Cup from player to player and skate with it in the TD Garden for the first time.

“I think that’s one thing everyone wants to do, is lift it on the home ice,” Marchand said. “That was nice to do.”

The Bruins won their sixth Stanley Cup title last season, sweeping Philadelphia out of the Eastern Conference semifinals in the process. The loss sent the Flyers scrambling to rebuild in the offseason, and among the new acquisitions was Jagr, the NHL’s leading scorer among active players and ninth overall.

The Flyers also acquired the rights to Bryzgalov and signed him to a nine-year, $51 million deal to replace the ineffective rotation they have used for the past several years. Also gone are offensive stars Mike Richards, their former captain, and Jeff Carter, the team’s leading goal scorer last season, who were traded on the same day in separate deals, in part to create salary-cap room to sign Bryzgalov.

The defending NHL champion Bruins were largely intact, with the notable departures of Mark Recchi to retirement and Michael Ryder and Tomas Kaberle as free agents. Defenseman Joe Corvo, who assisted on Marchand’s goal, was the major acquisition.

The sellout crowd stood throughout the pregame ceremony, and it wasn’t long before Marchand, a surprising star in Boston’s Cup run, scored a power-play goal on a pass from Tyler Seguin to give Boston a 1-0 lead.

It was the first goal in the NHL this season; Marchand also scored the last goal in the NHL last season, an empty-netter against Vancouver in Game 7 of the finals.

But the Flyers answered with two in the final minute of the first, including Giroux’s goal with 50 seconds left. With just 2.4 seconds remaining in the period, Voracek gave Philadelphia a 2-1 lead with a shot through Thomas’ legs.

“It was a big night for Boston, but we … did not come here to celebrate with them,” Bryzgalov said.