If you told me Maurice "Rocket" Richard was the greatest performer in Stanley Cup history, I certainly would not argue against you.
He won 8 Stanley Cups championships, including leading the Montreal Canadiens to 5 consecutive trophies from 1956 to 1960. When he retired in 1960, he held practically all the then-NHL playoff records: 82 goals, 126 points, 133 playoff games, 18 game winning goals, 6 overtime goals, and 7 hat tricks or better.
If you could only highlight one night of his long playoff career, the night of March 24th, 1944. Richard scored all 5 Montreal Canadiens' goals in a 5-1 victory over the Toronto Maple Leafs.
Following the game, Richard was named as the first, second and third stars of the game, the only time in NHL history that has happened.
Andy Lytle of the Toronto Star covered the game. Library and Archives Canada has made the article available to the public. There is also a French article, although it is unclear who wrote it and who published it.
The Canadiens went on to win the Stanley Cup. Richard led the playoffs in goal scoring with twelve goals in nine games. The 5 goals tied Newsy Lalonde's NHL record. Mario Lemieux, Darryl Sittler and Reggie Leach have since matched it.