Game 3 is Monday night in Buffalo.
"Anytime you look before the series, you look to take a split," Buffalo's Thomas Vanek said after scoring two goals. "Obviously when you win Game 1, you want to take that second one, too. But that's a good team over there."
Steady Brian Boucher relieved starting goaltender Sergei Bobrovsky in the first period and stopped 20 of 21 shots.
"The great thing about Boosh is, no matter what, you know what you are going to get," said James van Riemsdyk, whose first-period goal tied the game at 3-3. "He comes in and does a great job every time."
After making a nice spin-around move to avoid a defender and get space in the left circle, Ville Leino beat Sabres goalie Ryan Miller on the short side to give the Flyers a 4-3 lead with 6 minutes, 24 seconds left in the second period.
Before that power-play goal, the Flyers had been 0 for 7 with an extra skater (or two) in the game and 0 for 12 in the series. The second-seeded Flyers, who won last year's conference title as a seventh seed, finished the game 1 for 10 on the power play - they squandered a pair of five-on-three opportunities - while Buffalo was 2 for 8.
A little less than two minutes after Leino's goal, Scott Hartnell's shot deflected off Briere's left skate - he had his back to Miller - and into the net to push the Flyers' lead to 5-3.
There were 24 penalties, including 13 to Buffalo, and it prevented the teams from getting into a rhythm.
Despite the loss, Buffalo coach Lindy Ruff was pleased with the first two games.
"There was a lot of emotion in the building. They got a couple breaks on tipped shots that helped them get the lead," Ruff said. "I like where our club is at. . . . We get to go back home with a split."
Buffalo, seeded No. 7, got to within 5-4 when Cody McCormick converted Rob Niedermayer's cross from in front with 13:48 left in the third period.
Boucher made a key stop on Tim Connolly's left-circle drive with 3:48 to go, preserving the one-goal lead.
The series opener, Buffalo's 1-0 win on Thursday, was a tight-checking affair in which quality scoring chances were at a premium.
"It might have been the tightest game we played, defensively, all year," Flyers coach Peter Laviolette said before Saturday's opening faceoff.
And, so, naturally, the Flyers went out Saturday and played one of their loosest first periods in a while. Their penalty-killing unit was disorganized. Their rookie goalie, Bobrovsky, was flopping like a fish. Their defensemen weren't clearing bodies out front.
All of which helped Buffalo score three first-period goals, including two on the power play by Vanek. With O'Donnell caught out of position, Buffalo went on a three-on-one, and defenseman Andrej Sekera beat Bobrovsky from deep in the right circle, giving the Sabres a brief 3-2 lead with 7:30 left in the first period.
Exit Bobrovsky. Enter Boucher. (Also enter a reasonable goalie question: Who starts Game 3?)
"Just to change the momentum at that point," Laviolette said. "Boosh is a veteran goaltender. In a situation where they came back and took the lead, you get somebody in there who has some calmness to him, a presence to him and really take some pressure off our defensemen."
Luckily for the Flyers, the Sabres had just as many first-period defensive breakdowns. Playoff hockey? It looked more like pond hockey as the teams ended the first period deadlocked at 3-3.
The Flyers got first-period goals from Claude Giroux, Dan Carcillo, and van Riemsdyk. Giroux, who had just one goal in his previous 11 games, pounded the glass in glee after his goal gave the Flyers a 1-0 lead four minutes into the game.
Carcillo was so exuberant after scoring on a rebound, which gave the Flyers a 2-1 lead, that he raced down to the other end of the ice.
When It Came to Numbers, Giroux Made Them Count
Flyers winger Claude Giroux not only led the Flyers with two points (one goal and one assist) Saturday night, he also racked up big numbers in other categories:
Plus-minus: Plus-2, tied for team best.
Shots: 4, tied for team high.
Faceoffs won: 11, team high.
Faceoffs lost: 11, team high.
Time on ice: 21 minutes, 22 seconds, highest among team forwards, fourth among team skaters.
Hits: 5, second on team.
Blocks: 2, tied for second on team.
Shifts: 27, tied for first among team forwards, tied for fifth among team skaters.
Good news: The Flyers are 16-15 in series all-time when tied, 1-1.
Bad news: The Flyers are 14-17 all-time in Game 3 of a series that is tied, 1-1, after two games.
Contact staff writer Sam Carchidi at scarchidi @phillynews.com. Follow on Twitter at www.twitter.com/BroadStBull