PHILADELPHIA -- They were the popular choice among the prognosticators to win the Stanley Cup, but the Pittsburgh Penguins are going home empty-handed and deflated after a six-game series loss to the Philadelphia Flyers in the Eastern Conference Quarterfinals.

"Right now it is a shock, yeah," Pascal Dupuis said following the 5-1 series-clinching loss Sunday at Wells Fargo Center. "We didn't play the right way to win so we didn't win."

Here are the five biggest reasons why the Penguins couldn't make good on the lofty expectations that were placed on them after Sidney Crosby returned to the lineup on March 15:

1. PK problems never went away

The Penguins had the third-ranked penalty kill during the regular season. It was their biggest problem against the Flyers.

Philadelphia broke a franchise record for most power-play goals in a playoff series with 12. The Flyers connected on 12 of 23 power plays for 52.2 percent.

PHILADELPHIA -- Flyers center Danny Briere took one look at teammate Ilya Bryzgalov before Game 6 of his team's Eastern Conference Quarterfinal series against the Pittsburgh Penguins and had the feeling his team's goaltender was right where he needed to be -- Planet Bryz.

Ilya Bryzgalov

Goalie - PHI

RECORD: 4-2-0
GAA: 3.89 | SVP: 0.871

It also was a good thing for the Flyers, as Bryzgalov stopped 30 of 31 shots to backstop Philadelphia to a series-clinching 5-1 win against the Penguins on Sunday.

"Looking at him in the room, his preparation, you could tell he was in a zone," Briere said. "There's something special in his eyes today. And to see him play, he was composed. He was sure of himself. It's fun to see him that way."

It hasn't all been fun for Bryzgalov in his first season in Philadelphia, and certainly wasn't a lot of fun in the first five games of this series -- he entered with a 4.54 goals-against average and .848 save percentage in the first five games -- but when the Flyers needed him most, Bryzgalov was there.

PHILADELPHIA -- Sidney Crosby believed just like the rest of the Penguins.

Crosby thought his team was good enough to win the Stanley Cup. He liked the makeup, depth, composure of a team that he believed could make another long run in the Stanley Cup Playoffs.

Sidney Crosby

Center - PIT

GOALS: 3 | ASST: 5 | PTS: 8
SOG: 13 | +/-: -3

The Penguins didn't do execute well enough against the Philadelphia Flyers. As a result, they're going home early -- way earlier than most pundits expected -- after losing 5-1 in Game 6 of the Eastern Conference Quarterfinals at Wells Fargo Center on Sunday.

"There are no guarantees," Crosby said. "Everyone believed we had the team capable of doing that (winning the Stanley Cup), but that being said there's a lot of hockey to be played to do that. I don't think guys were caught looking too far ahead or caught up in the expectations. The expectations are there all year, they're high, guys understand that; but I think everyone does a great job of staying in the moment and worrying about the team ahead of us.

PHILADELPHIA -- In his 15 years of professional coaching, Flyers coach Peter Laviolette never encountered what happened between him and Claude Giroux before Game 6 on Sunday.

"When the best player in the world comes up to you and tells you, 'I don't know who you're planning on starting tonight but I want that first shift,' that says everything you need to know about Claude Giroux right there," Laviolette said.

Giroux was out to set the tone for the game, and he did it in the biggest way possible. He delivered a big hit on Penguins captain Sidney Crosby six seconds after the puck dropped, and -- just 26 seconds later -- he turned a Steve Sullivan giveaway into the game's first goal.

It was an opening shift that shook the Wells Fargo Center and started the Flyers on their way to a series-clinching 4-2 win.

"About 10 seconds before the puck dropped, he came over and told me, 'Watch the first shift,'" Danny Briere said. "And what he did, I didn't even know what to say to him."

Briere wasn't the only teammate left in disbelief at the way Giroux set the tone and drove the Flyers to the victory.

PITTSBURGH -- The longer the Pittsburgh Penguins keep their series against the Philadelphia Flyers going, the more time they give Evgeni Malkin to play a major role in it.

As the Penguins return to Philadelphia for Game 6 of the Eastern Conference Quarterfinals on Sunday afternoon, they're still waiting for the Art Ross Trophy winner and MVP contender to become the dominating scorer he was during his 109-point season.

Both of Malkin's goals so far came during a keep-the-series-alive 10-3 victory in Game 4 that prevented the Flyers from completing a four-game sweep. And while Malkin got off four shots in 21:14 of ice time during the Penguins' 3-2 win Friday in Game 5, he was visible mostly for the wrong reasons.

Not only did Malkin accidentally collide with teammate Sidney Crosby – giving both a jolt and Penguins fans a major scare – he took two penalties, one of which resulted in the Flyers' 11th power play goal of the series. Malkin also had five giveaways, three more than any other player on either team.

PITTSBURGH -- Memorable comebacks don't always begin with a defining moment or an otherworldly play. Sometimes they begin with one team planting a very tiny seed of doubt with the other.

Maybe it's turning away the same shot that's been going in the entire series. Maybe it is finally stopping a streaking power-play unit. Maybe it is getting a fluke goal. Maybe it is a big scorer finding the net.

As the Pittsburgh Penguins return to Philadelphia to play a Game 6 of the Eastern Conference Quarterfinals that wasn't being anticipated in either city only a couple of days ago, that's what they hope they've done with the Flyers: Planted a seed of doubt.

The Penguins gave the Flyers no reason to expect they wouldn't go down quickly and easily after losing 8-5 in Game 2 of the Eastern Conference Quarterfinals and 8-4 in Game 3 to fall down 3-0 in the series. The Flyers weren't just dominating the favored Penguins, they were embarrassing their rivals.

Penguins goalie Marc-Andre Fleury looked shaky and unconfident on every shot. NHL scoring champion Evgeni Malkin was off his game. The Penguins' penalty killing was allowing goals at a historic pace, and there were so many defensive breakdowns that the Penguins couldn't catalog them all. Even worse, they looked powerless to stop all the chaotic, high-scoring play that was going on around them.

VOORHEES, N.J. -- Philadelphia Flyers center Claude Giroux said if he had been told before his team's Eastern Conference Quarterfinal series against the Pittsburgh Penguins that his team would be coming home for Game 6 up 3-2 in the series, he would be pretty happy.

After taking a 3-0 series lead, though, having to prepare for Game 6 on Sunday (Noon ET, NBC, TSN) has to be a bit disappointing.

Following an optional skate Saturday here at Virtua Flyers Skate Zone, the players said the past needs to be left behind them, with the focus fully shifted to the next game.

"From my experiences, you can't really sulk from game to game or if things aren't going well," defenseman Matt Carle said. "You have to be ready for the next game. If you dwell on the past too much, it's going to affect the next game."

Giroux said he feels the team's collective mindset is in a good place. He said no one appears overly nervous or is squeezing the stick out of frustration over having missed two chances to close the series -- even if Giroux himself exhibited a fair bit of frustration himself, demolishing his stick after the final whistle by smashing it over the crossbar.

Sidney Crosby is arguably the biggest name in hockey. Evgeni Malkin is the Art Ross Trophy winner and one of the favorites to win the Hart Trophy as MVP. Almost every other team in the NHL would feel fortunate to possess either one; the Penguins pencil both of them into the lineup every night.

But in an elimination game -- and, no doubt, their biggest game of the season so far -- Pittsburgh's stars didn't carry the Penguins. Not even close. Instead, a must-win 3-2 victory against the Philadelphia Flyers in Game 5 of the Eastern Conference Quarterfinals on Friday was driven not by Malkin and Crosby, but by Jordan Staal and Marc-Andre Fleury, Tyler Kennedy and Steve Sullivan, Kris Letang and Brooks Orpik.

Yes, the "other" Penguins.

He wasn't bailing out on Marc-Andre Fleury despite such raggedly poor play by his goalie that the Penguins were in danger of being swept by their biggest rival in a series they were favored to win.

"I know Marc-Andre is going to be the guy in net for the next four games," Bylsma said.

Two games later – or at least one more than many in Pittsburgh and Philadelphia were forecasting he would play – Fleury is still standing. So are the Penguins after two consecutive victories in must-win games that tested their resiliency and Fleury's now-restored but previously badly shaken confidence.

PITTSBURGH -- If the Flyers are going to finally close out the Penguins in Game 6, Scott Hartnell said they're going to have to feel some pain.

Scott Hartnell

Left Wing - PHI

GOALS: 1 | ASST: 3 | PTS: 4
SOG: 11 | +/-: -2

"For us to win, we've got to bear down on our chances and we've got to block shots," Hartnell said. "It's been like that all year. You look at a team like the Rangers; when they're blocking 15, 20, 30 shots a game, I'm sure they're hurting after games. It seems like they're sliding right past us. The (Tyler) Kennedy one there, those things have to be blocked. We've got to realize that and get on that."

Kennedy scored the game-winner 9:53 into the second period on a shot that cleared both Wayne Simmonds and Pavel Kubina before going past Ilya Bryzgalov, who never saw it.