Maple Leafs win third straight Cup in 1949

There's an axiom in sports that says teams "can't just flip the switch" and revert to championship form. On April 16, 1949, the Toronto Maple Leafs finished doing just that. In the process, they became the NHL's first modern dynasty by winning the Stanley Cup for the third year in a row.
But for most of the 1948-49 season, a third straight Cup looked impossible.
By winning in 1947 and 1948, the Maple Leafs became the third team to repeat as champion since the NHL took control of the Cup in 1926. Neither the Montreal Canadiens (1930 and '31) nor the Detroit Red Wings (1936 and '37) were able to win a third straight championship, and for much of the 1948-49 season, it looked like the Maple Leafs would have the same fate.

The retirement of star center and captain Syl Apps left a void that was never filled. Toronto never won more than two games in a row all season and finished 22-25-13, a decline of 10 wins and 20 points from 1947-48. Still, they came in fourth, comfortably ahead of the Chicago Black Hawks and New Yok Rangers. Harry Watson led Toronto in scoring with 45 points (26 goals, 19 assists), but no one else reached the 20-goal mark.

Under the format used then, the Maple Leafs faced the second-place Boston Bruins in the Semifinals. They flipped the switch, showed little sign of their regular-season listlessness, and won the first two games at Boston Garden on the way to a five-game victory.
Next up was the Detroit Red Wings, the team Toronto had swept in the 1948 Final. Detroit had finished first in the regular season, 18 points ahead of the Maple Leafs. But the Red Wings were worn down by their seven-game victory against the Montreal Canadiens in the other Semifinal and never got untracked, while the Maple Leafs looked like the champions they had been in the previous two seasons.
Toronto won 3-2 in overtime and 3-1 in Detroit, giving them a 2-0 lead in the best-of-7 series. A 3-1 win on April 13 gave the Maple Leafs the chance for a second straight sweep in the Final.
Detroit took an early 1-0 lead when Ted Lindsay beat Turk Broda 2:59 into the game. But with the Maple Leafs turning up the pressure on the weary Red Wings, Ray Timgren tied the game midway through the second period and Cal Gardner put Toronto ahead to stay when he scored with 15 seconds remaining. Max Bentley's goal with 4:50 remaining in the third period capped Toronto's 3-1 win, its ninth in a row in the Final, and gave the Maple Leafs their third straight Cup.

"The Leafs just skated and hammered their rivals into the pipes," the Toronto Daily Star wrote.
The Maple Leafs became the first (and only) team in the Original Six era to finish fourth in the regular season and win the Cup. They're also the last team to win after finishing below .500.
Asked many years later to name the greatest team he'd been involved with, owner Conn Smythe wasted no time in replying, "The 1948-49 squad. That was the greatest Maple Leaf team ever."