In case the Philadelphia Flyers didn't already know it, they learned yesterday just how lucky they were a year ago when Bruins center David Krejci found himself in an ambulance, heading to Baltimore for urgent, season-ending wrist surgery. The dislocated wrist Krejci suffered in Game 4 of the Eastern Conference second-round playoff series cost the B's their best offensive threat, and was probably the decisive factor in their inability to close out a series they led 3-0. Anyone who might have disputed that Krejci's exit led directly to Philly's miracle comeback would have a tough time arguing the point after the crafty center produced two goals and two assists in the Bruins' dominant 7-3 victory yesterday over the Flyers in Game 1 of this year's second round. Philadelphia coach Peter Laviolette was asked about Krejci's great game, but went in a different direction. "Most of their lines had success against us," Laviolette said. But clearly, it was Krejci who owned this game, starting just 1:52 in, when he jumped in front of the Flyers net to backhand a Nathan Horton rebound past goalie Brian Boucher to quickly get his team going. In the second period, Krejci's deflection of defenseman Adam McQuaid's point shot past Boucher made it a 4-1 game and made a comeback by the home team pretty unlikely. It was a quite a turnaround for the 25-year-old Krejci, who was mostly contained by the Montreal Canadiens in the first-round series, producing one goal and no assists in the seven games. Aside from the obvious contributions of Horton (two overtime winners), the B's top line didn't play great against the Canadiens. But coach Claude Julien saw good reasons for the line's struggles. "Montreal really paid a lot of attention to (Krejci's) line," said Julien. "They really had some hard matchups against them. Montreal is a great defensive team. That's their strength, and they put their best players against that line. It made it tough for them." Krejci knew there was room for improvement.