If you trust your eyes, the Flyers have swung this series and seized control from the Chicago Blackhawks. If you believe your eyes, the impossible now seems more than possible.

The Flyers are two wins from the Stanley Cup.

So are the Blackhawks, of course. This is where you can't be sure of your eyes. Have the Flyers solved Chicago and goaltender Antti Niemi as completely as it appeared in Friday night's 5-3 victory? Or are we being fooled by home-ice mirages here?

"Right now, it looks like both teams play well at home," Flyers winger Simon Gagne said. "We have to go over there and try to win one game. It's not like we're two wins away. It's like we're one win from trying to get another win."

A few days ago, Chicago fans and media were gloating about how certain the Blackhawks were to close out the Flyers and win their first Cup in 49 years. After two games at the United Center, the Blackhawks were rolling.

After two games at the Wachovia Center, we can be sure of two things: This is now a best-of-three series. And if the Flyers were prohibitive underdogs at the start of the Finals, only a fool would call them that as the series heads back to Chicago for Game 5 Sunday night.

"It was our intention to come home and win both homes games," defenseman Chris Pronger said. "The momentum swings are always going to be a part of it. I think we understand it's up to us to build on what we've done here."

For three breathtaking games, these two teams were almost never separated by more than a single goal. The Blackhawks scratched out wins at home. The Flyers needed overtime to get back into the series in Game 3.

But some trends favored the Flyers, and they blossomed into full flower in Game 4. The Flyers delivered the first dominant performance of the series, taking a 4-1 lead and hanging on as the Blackhawks desperately tried to come back in the final period.

"We kind of relaxed a little too much when we got that 4-1 lead," Danny Briere said. "We escaped. Big relief. This was a good reminder that we can't let up."

In Game 3, especially the overtime, it looked more as if the Flyers were wearing Chicago down. Maybe that means the Blackhawks are also wearing down as the series goes on. Game 4 was a compelling argument to that effect.

"We wanted to start where we left off that last game in Chicago," Gagne said. "That's the type of hockey we want to play."

The Flyers controlled the game from the start, and the Blackhawks responded in frustration.

"They took some penalties early and we capitalized," Pronger said. "That was the game plan coming in."

Five seconds into a power play came the moment that really should concern Chicago. Mike Richards swooped down on defenseman Niklas Hjalmarsson behind the net, picked his pocket and the puck, then fired a backhand shot that beat Niemi.

Not only did the Flyers have the all-important first goal, they got it from their captain. Richards and his line had been shut down through three games. After coming up big again and again to get his team to the Finals, Richards was worrisomely absent from the score sheet.

"That's a hard-work goal," Pronger said. "I think it's his tenacious personality that we need to feed off. That's the type of effort we need night in and night out."

Ten minutes later, off another turnover by Hjalmarsson, Matt Carle fired the puck into an empty net. For the first time in the series, the Flyers had a two-goal lead.

Their third goal, which saw Niemi drift hopelessly out of position, was even more telling. It suggested that, as Peter Laviolette hinted in a crafty bit of gamesmanship, Niemi was feeling the pressure.

"I thought we were very generous in the first period in what we gave them as far as goals went," Chicago coach Joel Quenneville said tartly.

Niemi came way out of his net to square up on Kimmo Timonen as he coasted in from the point. All Timonen had to do was slide a pass to Claude Giroux, alone at the side of the open net, and it was 3-1, Flyers.

Meanwhile, the Flyers got their best game yet from Michael Leighton. He had no chance on Sharp's goal. The two third-period goals were hardly his fault, either. One was scored on a 5-on-3 advantage, the other caromed off sticks and skates as Jonathan Toews and Timonen skated into the crease at high speed.

Leighton is getting stronger, Niemi shakier. The Flyers seem to be getting stronger, the Blackhawks struggling with the pressure.

Is it all a mirage, caused by home ice?

The best-of-three Finals will decide.

Contact columnist Phil Sheridan at 215-854-2844 or psheridan@phillynews.com. Read his recent work at http://go.philly.com/philsheridan.