Game 4 of the Eastern Conference semifinal series will be in Ottawa on Wednesday.
Tyler Kennedy scored with just over a minute to play in the second period to give the Penguins a 1-0 lead. That goal stood up until Alfredsson tied it.
BRUINS 5, RANGERS 2
BOSTON (AP) — Johnny Boychuk broke a tie midway through the second period, and Boston scored two goals in the third to beat the New York Rangers and take a 2-0 lead in the Eastern Conference semifinal series.
Boston rookie Torey Krug scored the first goal before Ryan Callahan tied it for the Rangers in the first period. Gregory Campbell made it 2-1, and New York pulled even again on Rick Nash's goal in the second.
Games 3 and 4 of the best-of-seven series will be played in New York.
Rangers goalie Henrik Lundqvist, last year's Vezina Trophy winner, had his second straight tough game after posting consecutive shutouts in Games 6 and 7 of the first round against the Washington Capitals when the Rangers faced elimination.
Tuukka Rask was solid for Boston, stopping 35 shots.