Bruins defenseman Charlie McAvoy (73) celebrates with teammates after scoring the go-ahead goal Thursday night against the Calgary Flames. The Bruins won, 3-1. Charles Krupa/Associated Press

BOSTON — Charlie McAvoy scored the go-ahead goal in his season debut and the Eastern Conference-leading Boston Bruins remained perfect on home ice, beating the skidding Calgary Flames 3-1 Thursday night.

Linus Ullmark made 31 saves and Connor Clifton also scored as the Bruins improved to 8-0-0 at TD Garden. David Pastrnak added an empty-net goal for Boston, which is 12-2-0 overall.

Noah Hanifin scored for the Flames, who dropped their seventh straight.

Calgary swarmed the Bruins early, holding them without a shot during the first seven minutes. The Flames scored at the tail end of a power play, as Hanifin got his first goal of the season at 4:43 of the opening period.

Clifton followed up his own shot at 16:38 to tie it.

McAvoy’s goal came on the power play at 18:27 of the second, with traffic in front of Calgary goalie Dan Vladar, who finished with 24 saves.

McAvoy, the Bruins’ top defenseman, was expected to be off the ice for six months after undergoing shoulder surgery in June. The 24-year-old had 10 goals and 56 points in 78 games last season, including 21 points on the power play.

NOTES: McAvoy played 18:53. He averaged a team-high 25 minutes of ice time last season. … Clifton and McAvoy became the 17th and 18th players to score goals for the Bruins this season. … With McAvoy reinstated off long-term injured reserve, the Bruins waived defenseman Mike Reilly with the intention of sending him to Providence of the AHL. … Milan Lucic, who won a Stanley Cup with Boston in 2011, returned with the Flames. Lucic, 34, is in his fourth season with Calgary. … The Flames started the season with five wins in their first six games. They fell to 5-5-2 overall after dropping all three games on their road trip. … The Flames outshot the Bruins 37-22. … Boston is 6-0-0 against Western Conference opponents.