In Toronto, Bobby Clarke contributed two assists, including a pass to Mark Taylor for a goal at 8:27 of the third period that lifted Philadelphia into the tie with Toronto.
Taylor took Clarke's centering pass and fired a shot that eluded Leafs goalie Mike Palmateer and skipped under the cross bar.
Toronto's Rick Vaive had given the hosts a 2-1 lead at 4:07 of the final period when he scored his 44th goal of the season.
Philadelphia's John Paddock opened the scoring at 5:06 of the second period, converting Clarke's pass past Palmateer's stick side from 40 feet out.
Just seven seconds into the final period, Toronto center Dan Daoust made it 1-1 with his 13th goal of the season. His backhander deflected into the net off the right arm of Flyer goalie Bob Froese.
Darryl Sittler, who was traded to the Flyers last season after 11 years with the Leafs, during which he became Toronto's all-time leading scorer with 389 goals and 969 assists, made his first apperance of the season in Maple Leaf Gardens.
He was held to three shots on net, including two on a third-period breakaway.