The last time the 'hawks won the championship was in 1961. Their win ends the longest active championship drought in the NHL.
Officials said the city of Chicago will celebrate the 'hawks' historic win with a parade and rally on Friday downtown.
Patrick Kane sneaked the puck past Michael Leighton 4:10 into overtime and stunned Philadelphia to lift the Blackhawks to a 4-3 overtime win in Game 6 on Wednesday night for their first championship since 1961.
No one but the Blackhawks appeared to know what was going on for a few frozen moments. Kane and his linemates seemed the only players on the ice who knew the puck found the side of the net. The goal light never went on, but that didn't stop most of the Blackhawks from storming the ice and mobbing each other in celebration.
The review was a short one and Kane will go down as scoring one of the biggest winners in team history.
"I was just hoping to God it was just an actual goal," said captain Jonathan Toews, the Conn Smythe Trophy winner as playoff MVP. "They came back hard in the third and we just stuck with it."
Kane raised his arms right away and skated behind the net, knowing the goal was good. While the Flyers sat on the bench in stunned silence with confused looks, the Blackhawks began to celebrate in their own end around goaltender Antti Niemi.
"I knew it went in right away," Kane said. "What a feeling. I can't believe it. We just won the Stanley Cup. I can't believe this just happened. ... It's something you dream about, scoring the final goal in the Stanley Cup finals."
Before reaching the group hug, Kane stooped to pick up some loose ice shavings -- looking like a mischievous kid on Christmas ready to throw a snowball in the backyard.
"There's so many great things about winning a Stanley Cup. This is it," Toews said. "This is the best feeling you can ever get. I just can't believe it's happened."
Toews was first to touch the Cup, taking it from commissioner Gary Bettman and hoisting it above his head in triumph. Marian Hossa, whose last two attempts at a title were denied the last two years with Detroit and Pittsburgh, was next. He lifted it and bench-pressed the big trophy, snapping his head back in exhilaration.
"I'm so happy I finally did it," Hossa said. "We couldn't just put our heads down. We had to work, and we knew we could do it."
The Blackhawks completed their revival from the bottom of the NHL to holding the silver trophy on the strength of rising stars Kane and Toews.
Niemi was solid in goal to help the Blackhawks wrap up their most successful season since Bobby Hull and Stan Mikita led the way 49 years ago.
It ends the longest active championship drought in the NHL. Kane is the first player to score the Stanley Cup clinching goal in overtime since Jason Arnott did it for New Jersey at Dallas in 2000.
"I heard the sound, it was a funny sound," coach Joel Quenneville said of the Cup-winner. "Nobody knew where the puck was. Kaner thought it was in."
Fitting in a series where neither team had much wiggle room, this one needed OT.
Just when it appeared the Flyers season was over, Scott Hartnell squeezed out another clutch goal.
With the offense revved into desperation mode, Hartnell was leveled by Toews right in front of the crease as he knocked a loose puck in to make it 3-3 with 3:59 left in the third.
He raised his arms while flat on his back.
Knocked down, never out.
The Flyers faithful turned their white towels into rally symbols only moments after they could have been used for surrender.
The fans politely applauded when the game was over, but the few thousand who stuck around booed as the Blackhawks took their turns hoisting the silver trophy. A few hundred Blackhawks fans went wild as the team took a picture with the Cup.
The Blackhawks could almost taste the champagne at the end of the second period. They ruthlessly attacked the Flyers and it paid off with two should-have-been-stopped goals against Leighton.
Leighton, who had been flawless at home this postseason, couldn't come up with two crucial saves and that helped put Chicago in the driver's seat.
Andrew Ladd, an injury scratch the first three games, deflected Niklas Hjalmarsson's slap shot from the circle with 2:17 left in the second. That made it 3-2 and nearly stood as the winner.
His goal followed Patrick Sharp's soft wrister that scooted under Leighton's left skate to tie it a 2 midway through the period. Sharp's 11th goal of the postseason came during a 4-on-4.
Niemi was barely tested and had as much time to watch the action as the orange-clad fans. Daniel Briere beat him for a 2-1 lead when he came streaking down the right side and went high glove side off a crisp pass from Ville Leino with 12 minutes left. Briere carried through the Flyers all the way to the brink of the title.
There were 40 goals scored in the first five games, the most for a finals since 1981. This one was a goalie's duel early with only a power-play goal from each team in the first period.
The Blackhawks couldn't find the back of the net, but they had their chances.
Chicago pounded Leighton from all angles and were outshooting the Flyers 14-3 at one point late in the first.
Chris Pronger, who had one of the worst playoff performances of his career in Game 5 (minus-5), was penalized twice in the first. His antagonistic actions came after a day after he was the subject of an unflattering picture of him in a skirt in the Chicago Tribune.
Pronger's penalty for high sticking was still being announced when Byfuglien popped out to face the net and one-time a pass from Toews past Leighton with 3:11 left.
Amazingly, the Flyers didn't even attempt a shot on their first two power-play chances. The special teams unit that had been so effective during their first Stanley Cup finals run since 1997 had suddenly gone dry.
That is, until Hartnell bailed them out.
He backhanded the puck through Niemi's legs -- he couldn't even get his pads on it -- with 26.5 seconds left to tie the game. Hartnell barked at the Blackhawks and a home crowd on edge suddenly roared back to life.
One goal was the jolt the Flyers needed to make up for a lackluster first 20 minutes.
The Flyers simply ran out of comebacks.
This Flyers team has mastered the art of the comeback, starting all the way back on the last day of the regular season when a shootout win clinched a playoff spot. It became the third team in NHL history to win a series after losing the first three games when it eliminated Boston in the Eastern Conference semifinals, and evened the Stanley Cup at 2-all after losing the first two games at Chicago. It wasn't enough and the Flyers are looking for their first Stanley Cup since winning consecutive championships in 1974 and 1975.
The Associated Press contributed to this report.