Kuraly put the Bruins ahead 2-1 at 12:28 with a shot from the left side off the rush that went in off the far post.
"I'd be lying if I said that came off my stick and I thought I was going to score," Kuraly said. "We think offense, just simplify and start with getting the puck on the net. Who knows if that goes in or doesn't, sits in front of the net, rebound. No one knows where it's going off the goalie, and for our line, we think that's a good way to start to play offense. ... I just told myself get the puck to the net and wasn't sure that one was going to go in, but when it does, I'll put my hands up and [celebrate]."
Marchand tied the game 1-1 at 12:01. Elliott stopped Charlie McAvoy's shot from the point, but Marchand dove into traffic in front of the net and poked in the puck.
The goal extended Marchand's point streak to eight games (six goals, six assists).
"Personally, you go from pitching a perfect one to losing it in like a span of a minute," Elliott said. "It's frustrating. It's on me, and that's one we should have come up with there."
Van Riemsdyk scored a power-play goal 27 seconds into the third period to give the Flyers a 1-0 lead when he redirected a shot by defenseman Erik Gustafsson.
The goal extended van Riemsdyk's point streak to six games (three goals, eight assists).
Philadelphia outshot its opponent for the second time in 12 games, which coach Alain Vigneault said was a sign of better 5-on-5 play.
"I liked the way we played, I like the way we competed," Vigneault said. "I don't like the final result, but for the most part I liked our 5-on-5 game tonight."
Joel Farabee had the Flyers' first penalty shot of the season at 16:25 of the second period after he was hooked by Jakub Zboril on a breakaway. The Philadelphia forward tried to beat Rask between his pads, but the Boston goalie made a stick save.
NOTES: Bruins center Patrice Bergeron played his 1,100th NHL game. He's the third to play that many with Boston, after Ray Bourque (1,518) and Johnny Bucyk (1,436). ... Bruins center David Krejci had an assist on Kuraly's goal to extend his point streak to four games (four assists). ... McAvoy extended his point streak to seven games (one goal, nine assists). ... Pastrnak had an assist on Marchand's goal and has scored eight points (five goals, three assists) in four games since returning from Sept. 16 hip surgery. ... Flyers defenseman Philippe Myers missed the game because of an upper-body injury. Vigneault said he hoped to have an update Saturday. ... Philadelphia goalie Carter Hart was out after he had back spasms during the morning skate. Alex Lyon was recalled from the taxi squad to back up Elliott. Hart is expected to practice Saturday. ... The Bruins and Flyers will next play each other at Lake Tahoe for the Honda NHL Outdoors Sunday on Feb. 21.
