Flat and stupid is no way act in the Stanley Cup playoffs.

On Thursday, the Maple Leafs proved that with a dismal and dumb 5-0 loss to the Senators in Game 1 of their Eastern Conference semifinal series.

After an emotional and physical seven-game first-round battle against the Islanders, the Leafs figured to be a bit flat in their "Battle of Ontario" opener against the Sens. A night earlier, the defending champion Avalanche suffered a similar emotional letdown, dropping a 6-3 decision to the Sharks after surviving a tough seven-game series with the Kings.

But, unlike Colorado, Toronto compounded its problem by starting a comical parade to the penalty box. On the night, the home team played shorthanded for a ridiculous 21:19 of the 60 minutes. Due to the Leafs' lack of discipline, the Senators enjoyed 12 power-play chances. They converted three of those opportunities, including both ends of a double minor for high sticking to Alexander Mogilny in the first period.

Not satisfied with just hooking and holding, Toronto committed a wide variety of infractions. The Leafs truly tested referees Dan Marouelli and Mick McGeough, who responded by whistling them for nine different types of minor penalties. Among Toronto's crimes: goaltender interference, closing your hand on the puck, and the always popular too many men on the ice.

If Pat Quinn's troops could kill penalties, perhaps they would've survived their own foolish behavior. But, they can't. In their eight playoff games so far, the Leafs have surrendered 14 power-play goals. They've allowed two or more in half of them.

Thus far, the Leafs' playoff worst penalty-killing unit -- which ranked 16th during the regular season -- has been too passive in pressuring their opposition. And, they've been much too soft below the dots in their end. Defensemen Tomas Kaberle (a wonderfully gifted offensive defenseman), Aki Berg and Jyrki Lumme have been particularly bad around their own net in penalty-killing situations.

Clearly, if Quinn can't turn their penalty killing around, the club will have to play a lot smarter in this series. At least, if they have any desire to win it.

In Game 1, smarts and desire just weren't part of the Maple Leafs' gameplan -- as evidenced by the result. For Toronto's sake, both elements had better be present in Game 2.

E.J. Hradek writes hockey for ESPN The Magazine. E-mail him at ej.hradek@espnmag.com.