I can't remember - was Niemi a backup or were they platooned?
If so, then that's probably the first backup the Flyers have beaten in a few years.
I used to joke that the Flyers were playing "Bob the goalie" whenever it was announced they were facing a backup. Because the Flyers now have "Bob the goalie," that joke is on hiatus. However, it seems to me that they fared better against starters than they did against their backups over the years. The only exception is Brodeur, whose backups have played like six games in the last 15 years.