Van Riemsdyk and Jagr scored 52 seconds apart late in the first period to erase the Red Wings' 1-0 lead.
Van Riemsdyk tied it 1-all with 2:34 left in the opening period and Jagr gave the Flyers the lead for good with 1:42 remaining in the first.
The Flyers' victory came a night after a banana was thrown from the stands as Wayne Simmonds scored during a shootout. Simmonds, who is black, did not play Friday night but was seen signing autographs.
Pacioretty converted Montreal's first shootout attempt after scoring a pair of power-play goals in the second to key the Canadiens' comeback from a 3-0 deficit. The Canadiens' left wing played his second game since returning from a broken vertebra, the result of a controversial hit by Boston's Zdeno Chara on March 8.
Craig Anderson played the entire game for Ottawa, stopping 29 shots.
ST. PAUL, Minn. (AP) - Dany Heatley scored twice in his Minnesota debut, including the winner in overtime for the Wild.
NEWARK, N.J. (AP) - Defenseman Brendan Bell snapped a tie with 3:04 left, and New York earned a preseason split with New Jersey.
Bell flipped a shot from the right point that got past Devils goalie Martin Brodeur, giving the Rangers the win. New York lost 2-1 in overtime to New Jersey on Wednesday night in Albany, N.Y.
Brad Marchand added a goal and an assist.
Hillen and Mueller scored 1:37 apart against Carolina backup goalkeeper Justin Peters, who entered the game at the start of the third.
Alexei Ponikarovsky had two goals for Carolina.
Carolina goalkeeper Cam Ward saw his first action of the preseason after being slowed by upper body stiffness since the opening of training camp a week ago. Ward started and played 40 minutes. He gave up a goal to Nashville's David Legwand at 17:58 of the second period.
TORONTO (AP) - Jason Pominville scored on the power play at 14:42 of the third period and Buffalo won its third straight preseason game.
The Maple Leafs killed off four previous penalties before Pominville connected for the Sabres with the man advantage.
Phil Kessel tied it for Toronto in the second on a power-play goal.
Shannon capitalized on another man-advantage situation at 6:31 of the second period, then scored again at the 12:55 mark.
Jack Skillie broke through for the Panthers on a power play 4:20 into the third after the Panthers came up empty on six opportunities in the first two periods.
Michal Repik scored Florida's other goal 12 minutes later.
Markstrom finished with 28 saves.
CHICAGO (AP) - Rookie Brandon Saad scored the winner with 3:21 left in the third to lift Chicago to its first preseason win.
Viktor Stalberg scored two goals early in the third period for Chicago. Saad set up Stalberg's first score.
Grachev scored on a power play at 8:06 of the first period on a pass from Jamie Langenbrunner.
Cracknell wristed a shot from the center of the right circle past goalie Semyon Varlamov at 5:02 of the third and Backes scored an empty-netter with just over 58 seconds left in the game.
Paul Stastny scored for the Avalanche from up close 13 seconds later, but it wasn't enough and the Avalanche fell to 0-2 in exhibition play.
Colorado rookie Tyson Barie ended Jake Allen's shutout bid with a shot from the top of the left circle at 12:48 of the third.