Biggest Upsets in NHL Playoff History

The Stanley Cup Playoffs in the NHL can be unpredictable, with plenty of lower seeds advancing in the postseason. Unlike other sports, where higher seeds tend to reign supreme, this tournament is one where anything can happen. These massive upsets, in particular, were proof that you can throw seeding out the window when the NHL playoffs roll around, and that no team is safe when the Cup is on the line.
Ducks over Red Wings - 2003
The Detroit Red Wings were convincing favorites to beat the Anaheim Ducks in the 2003 Western Conference quarterfinals. After all, the Red Wings were the team that was used to having success in the playoffs, while the Ducks were still known mostly for being birthed from a kids' movie franchise. But it looked like the Ducks were the playoff-seasoned team in this series, as they bounced the Wings in the first round in a shocking sweep.
Anaheim managed to keep the Wings under three goals in all four games of the series, with their most impressive defensive performance coming in the first game of the series. That first game set the tone for the series, with the Ducks winning 2-1 in a three overtime classic. During that game, Ducks goaltender Jean-Sebastien Giguere took on a whopping 64 shots and only let one of them through. It was the first of many brilliant performances by Giguere en route to an appearance in the Stanley Cup Final.
Wild over Avalanche - 2003
The Minnesota Wild were only a few seasons into their existence as an NHL team when they made the playoffs as a six-seed in the 2003 season. But they were stuck taking on the Colorado Avalanche, which had been one of the most successful teams in the league during that era. With the Wild going down three games to one after a loss in the fourth game of the series, it looked like both teams would continue along their respective trajectories. But a courageous change in goaltenders helped the Wild pull a huge upset and buck the trends of history. After game four, which was the third straight game starting goalie Dwayne Roloson gave up three goals in a loss to the Avs, the Wild switched to Manny Fernandez between the pipes. And Fernandez rewarded the Wild with three straight wins in net, where he gave up two goals in each of the final three games of the series. The Wild met the aforementioned Ducks in the conference finals, where they were swept after a season to be proud of.
Canadiens over Capitals - 2010
In another first-round shocker, the eight-seed Montreal Canadiens looked likely to bow out in the first round against the Washington Capitals. The Capitals had won the Presidents' Trophy for their performance in the regular season and had built up a huge lead in this Eastern Conference quarterfinal series. But the Canadiens didn't give up and managed to put together three near-flawless performances when they needed them most to send the Capitals' collective jaw to the floor.
Washington, after losing the first game of the series, won the next three to go up 3-1 in the best-of-seven series. In those three wins, the Caps averaged just under six goals per game, and looked unstoppable. From there, though, the Habs locked up the Caps' potent attack. The Canadiens allowed just three total goals in the final three games of the series to complete the comeback, which culminated with a gritty 2-1 win in Washington to seal up the series. Montreal made it all the way to the Eastern Conference Finals, where they lost to the seven-seed Philadelphia Flyers in a battle of Cinderella stories.