Swayman, 22, was called up Monday, and became the fourth goalie to play for the Bruins this season. While Boston may have high hopes for the former fourth-round pick, the Bruins probably weren't expecting this on short notice. His presence was needed after Jaroslav Halak tested positive for COVID-19 earlier in the week.
"What an incredible experience," Swayman said. "To get a win here in Philly, it means everything."
The Flyers tested Swayman with 25 shots in the second period, including a Scott Laughton breakaway that he calmly stopped. Swayman, a Hobey Baker finalist last season as best player in college hockey at the University of Maine, only had to make four saves in the third period.
"He deserved much better support than we gave him," coach Bruce Cassidy said, "and he eventually got it in the third."
After his junior season with the Black Bears ended early because of the COVID-19 pandemic, he elected to skip his final season and sign a three-year, entry-level deal with the Bruins. He is viewed by the organization -- along with Dan Vladar, who is also active on the Bruins roster because Tuukka Rask is still sidelined with an undisclosed upper-body injury -- as the team's future in net. Vladar made 29 saves for the Bruins vs. the Flyers on Monday.
"It's a game. And it's a game that I love," Swayman said. "And I enjoyed every second of it."
In his final season with the Black Bears, Swayman went 18-10-5 with a 2.07 goals-against average, and a .939 save percentage. He led Maine to an 18-11-5 finish, good for fourth place in Hockey East.
Swayman's effort took a headline or two away from Patrice Bergeron, who recorded a hat trick and reached 900 career points in the win. Brad Marchand added a short-handed goal as the Bruins won for the second time in three games. Bergeron's final tally was into an empty net.
Jakub Voracek and Shayne Gostisbehere scored for the Flyers, and teammate Carter Hart, who has been ineffective for more than a month, did not break out of his slump in goal, getting outplayed by Swayman on the other side.
"It's a tough loss," Flyers forward Oskar Lindblom said, "but there's plenty of points still out there."
The Associated Press contributed to this report.