"It's huge for us and we have to keep pushing forward," said Simmonds, whose team moved into second place in the Metropolitan Division.
Mason was asked if the Flyers are in the Penguins' heads.
"I know the boys in this dressing room love playing against them," he said. "Whether we're in their head or not, we don't really care. . . . It's a fun game to play against them, and we're just happy with the four points this weekend."
Pittsburgh, which almost overcame an early 3-0 deficit, nearly tied it, but Mason (20 saves) got a piece of Crosby's left-circle drive with about 30 seconds left and the puck trickled wide. A short time later, Crosby got in close, but was denied by the iron after a sequence in which the referees appeared to miss an offside call.
Crosby, the NHL's leading scorer, and Evgeni Malkin were pointless in the two weekend games. Sean Couturier, who has become one of the league's best defensive forwards, took turns shadowing Crosby and Malkin on Sunday.
The Penguins gave the Flyers three early power plays and trailed, 3-0, before rallying in the last two periods.
"I don't see any positives in only playing 40 minutes," Crosby said.
For the second straight game, the Flyers frustrated Pittsburgh's vaunted power play. The Penguins were 0 for 4 Sunday and 0 for 5 Saturday. In both games, Matt Read scored a shorthanded goal.
Pittsburgh, playing without five key players who were injured, got to within 3-2 when defenseman Matt Niskanen scored on a point drive with 14 minutes, 10 seconds left in the second period. Joe Vitale set up a screen in front of Mason.
A little over six minutes later, the Flyers increased their lead to 4-2 on Read's shorthanded goal on a two-on-one.
But the Penguins cut the deficit to 4-3, taking advantage of a Michael Raffl turnover as Jayson Megna converted a two-on-one with 3:41 to go in the second.
In the opening period, Simmonds had a hand in all three goals as the Flyers silenced a stunned home crowd by building a 3-0 lead and sending goalie Marc-Andre Fleury to an early exit with 6:19 left in the stanza.
Fleury was booed loudly as he skated to the bench and was replaced by Jeff Zatkoff. Fact is, Fleury could have sued for nonsupport. The Penguins, their defense weakened by injuries to Kris Letang and Paul Martin, gave the Flyers too much time and space throughout the first period.
"I think our team will get confidence from this," coach Craig Berube said of the weekend sweep. "Anytime you can beat Pittsburgh twice it's a big boost. . . . But I try to keep our team even [keel] - don't get too high, don't get too low. We've got a game Tuesday and we have a big week coming up."
The Flyers play their next four games at home, starting Tuesday against the defending Stanley Cup champion Chicago Blackhawks.