What teams have won Stanley cup after losing the first game?

Answer 1

Since the "best of seven" format was instituted for the 1939 Stanley Cup:

2004: Tampa Bay Lightning (over Calgary Flames) (7 game series)

2002: Detroit Red Wings (over Carolina Hurricanes) (OT) (Red Wings won 4 straight after losing the opening game)

1999: Dallas Stars (over Buffalo Sabres) (OT)

1994: New York Rangers (over Vancouver Canucks) (OT) (7 game series)

1993: Montreal Canadiens (over Los Angeles Kings) (Canadiens won 4 straight after losing the opening game)

1991: Pittsburgh Penguins (over Minnesota North Stars)

1986: Montreal Canadiens (over Calgary Flames) (Canadiens won 4 straight after losing the opening game)

1985: Edmonton Oilers (over Philadelphia Flyers) (Oilers won 4 straight after losing the opening game)

1979: Montreal Canadiens (over New York Rangers) (Canadiens won 4 straight after losing the opening game)

1974: Philadelphia Flyers (over Boston Bruins)

1971: Montreal Canadiens (over Chicago Black Hawks) (OT) (7 game series) (Black Hawks won first two games)

1967: Toronto Maple Leafs (over Montreal Canadiens)

1966: Montreal Canadiens (over Detroit Red Wings) (Canadiens won 4 straight after Red Wings won first two games)

1947: Toronto Maple Leafs (over Montreal Canadiens) (Canadiens won game one 6-0)

1942: Toronto Maple Leafs (over Detroit Red Wings) (Maple Leafs won 4 straight after losing the first three games)

Answer 2

The 1942 Toronto Maple Leafs were down 3-0 to the Detroit Red Wings and came back to win 4-3. The New York Islanders were down 3-0 to the Pittsburgh Penguins and came back to win 4-3.