The Finnish netminder stopped 49 of the 52 shots he faced in regulation and overtime, then shut the Flyers down on four out of five shootout attempts.
The win was Rask's ninth in his last 10 appearances, bringing his record for the season to a lofty 34-14-5, with the 34 victories easily representing a career high.
Rask's previous high-water mark was 22 wins, a total he achieved in 2009-10 when current Dallas Stars goalie Tim Thomas was still with the Bruins. The Finn entered that season with just five career appearances, but by the end of the year he'd displaced Thomas as the Bruins' top netminder.
Unfortunately for Rask—who led the NHL in goals-against average (1.97) and save percentage (.931) in 2009-10—Thomas returned to form the following season and served as the Bruins' No. 1 goalie in both 2010-11 and 2011-12.
Despite starting his career in extremely promising fashion, Rask had just 44 career wins through three NHL seasons.
It wasn't until 2012-13 that he took over as the top goaltender, and Rask has subsequently made Bruins fans forget all about Thomas, posting a superb 53-24-10 record over the last two seasons.
It may have taken five seasons for the first 100 wins, but the next 100 should come much faster.