Briere had a goal and three assists, while Timonen had a pair of assists.
Mike Richards secured the Flyers' fourth straight win by scoring on a breakaway to give the Flyers a 4-2 lead with 8:24 remaining.
Scott Hartnell scored two goals, including an empty-netter.
Goalie Sergei Bobrovsky (38 saves) overcame a shaky first period and notched his first win since Dec. 15. The rookie is 16-6-3.
The Flyers have the NHL's best road points percentage (.738) - and they have the fewest regulation losses (four) away from home. They are 14-4-3 on the road, and 5-0-1 in their last six games in Buffalo.
Briere, snubbed from the all-star team even though he is the Flyers' top goal scorer - and tied for sixth in the league - tied the score at 2 after depositing a feed from fellow all-star snubee Timonen with 1:49 left in the second period.
Timonen had joined the rush after leaving the penalty box, "and it created a scramble," Briere said. "It was kind of like a two-on-one, two-on-nothing break. I was just trying to get open and I knew Kimmo was going to try and find me backdoor. The puck was coming over a little slow. I was just trying to find a way to get it over [Miller's] shoulder."
Briere spent three-plus seasons with the Sabres.
"It is always a little special scoring a goal against your ex-team," he said. "Maybe it's less and less every time you come back, but there is always going to be a little something there."
Until a late second-period flurry, the Flyers had little attack time in the first 40 minutes, when they were outshot, 29-16.
Bobrovsky made just his fourth start in the last 13 games - and he looked rusty in the opening period. It was his first start since Dec. 31 in Anaheim, and his first since Michael Leighton was sent to the AHL's Phantoms.
Brian Boucher, one of the league's hottest goalies, had started the previous three games, including 4-2 and 2-1 wins over New Jersey.
"Boosh has had success against New Jersey, so we kind of had a set plan in place," coach Peter Laviolette said before the game. "But in the back of my mind, Bob had beaten Buffalo once already and we wanted to get him back in there."
On Oct. 26, with Bobrovsky making 33 saves, the Flyers defeated the Sabres, 6-3.
Bobrovsky entered the night with a 1-2-1 record and 4.25 goals-against average in his last five games, four of which were starts.
Buffalo built a 2-0 lead in the game's first 9:59.
Five minutes into the game, Paul Gaustad scored on a rebound. About five minutes later, Cody McCormick took a rebound off the back boards and knocked a backhander past a slow-to-react Bobrovsky, who failed to cover the post.
Hartnell trimmed the deficit to 2-1 as he tipped in Timonen's point drive with 7:19 left in the first period. It was just Hartnell's second power-play goal of the season.
The Flyers nearly tied it, but a sprawling Miller stopped Jeff Carter - who was unable to lift the puck - on a rebound while on a power play with 13:13 left in the second.
With 2:10 to play in the period, Miller also made a nice stop on Matt Carle in front after he was set up by Carter.
Bobrovsky settled down in the second period and made a handful of impressive saves, including one on rookie center Tyler Ennis in front.
The Flyers started the second half of the season atop the Eastern Conference. They had their second-best record at the midway point in the last 25 seasons.
Buffalo entered the night 10th in the East, eight points behind eighth-seeded Montreal. Surprisingly, the Sabres were 4-1-1 since Derek Roy, their leading scorer with 35 points, suffered a knee injury that is expected to sideline him for the rest of the season.
Contact staff writer Sam Carchidi at 215-854-5181 or scarchidi@phillynews.com.
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