"It's always frustrating when you're losing. But by the same token, it happens to teams," Snider said. "We were hoping for a good trip, and it could have been better.
"If we hadn't given up that goal in San Jose with 15 seconds to go, we wouldn't have lost in regulation in any of these games. So I'm very proud of this team. I've got a lot of confidence in our players. We've got a lot of good kids, and I think we're going to get better and better."
The victory was only the second in 12 games for the Flyers, who avoided tying the franchise record of 10 consecutive road losses.
"I think you have to look at this as a turnaround for us, I hope," Snider said. "I'm very pleased with what I've seen. Mason did the job today -- but when you come into this building, it's tough no matter who you are."
The players weren't intimidated at all by Snider's presence at a road game. Quite the contrary.
"Ed's really good with us, and he's first class," Simmonds said. "He's been unbelievable to us, and we owe it to him and the rest of the organization to be better."
Justin Williams scored for the Kings, who limited the Flyers to just 16 shots against Jonathan Quick. Los Angeles was 0 for 5 on the power play against a penalty-killing unit that came in with the league-worst 74.4 success rate.
"You know if you don't have your game against those guys, you're going to pay for it," Mason said. "They're a measuring stick for the entire league right now and have been a model of consistently for the last few years -- and they have two Stanley Cups to show for it. So when you see them on the schedule for the next game, you've got to make sure you're prepared right from the start."
Los Angeles, coming off its third shutout victory in four games and second in a row, fell behind 1-0 at 4:35 of the first period when Giroux got a pass in the slot from Mark Streit and beat Quick high to the stick with a 25-foot wrist shot.
"We weren't prepared for the 1:00 game today. We weren't ready to go right away and we got behind," Williams said. "At the same time, we certainly had our chances to come back and atone for our start. But the power play didn't get it done."
Simmonds, who spent his first three NHL seasons with the Kings before he was traded to Philadelphia with Brayden Schenn for Mike Richards in June 2011, made it 2-0 at 2:08 of the second period with his 11th goal.
"They're the Stanley Cup champs and they've won it two of the last three years, so you've got to bring your `A' game against these guys, obviously," Simmonds said. "They play a heavy game. They've got a lot of big players on their team and they all finish their checks. I thought we did a good job of competing today, and it shows that we can hang in there with the big boys."
Williams ended Mason's shutout bid during a goalmouth scramble with 15:51 left in the third period, flipping his sixth of the season over the fallen goalie after Mason made the save on defenseman Robyn Regehr's wrist shot.
The Kings had a great chance to tie it midway through the third, when Mason left a rebound after stopping Anze Kopitar's 40-foot wrist shot with his glove. But Richards backhanded the puck over the crossbar.
NOTES: The Flyers beat the Kings 3-2 on Oct. 28 at Philadelphia with Schenn's overtime goal. The last time the Flyers played at Staples Center on Feb. 1, 2014, Simmonds scored his 100th NHL goal and Mason made 35 saves in a 2-0 victory. ... Richards, who averaged 28 goals during his final four seasons in Philadelphia, has 45 goals in 231 regular-season games with the Kings. ... Giroux entered Saturday second in the league in shots on net with 107, four behind Alex Ovechkin. ... Kings RW Marian Gaborik missed his fourth straight game because of an upper body injury. ... The Kings begin a five-game road trip Tuesday night at Buffalo.