Instead of the Red Wings becoming the NHL's first repeat champion since winning titles in 1997 and 1998, this turned into a Penguins party. The last time Pittsburgh won the Cup, in 1991 and '92, it was captained by owner Mario Lemieux.
Pittsburgh goalie Marc-Andre Fleury was stellar in making 23 saves - none bigger than the one he made with one second left as he dived across the crease and knocked away a shot by Niklas Lidstrom.
"I knew there wasn't much time left," Fleury said. "The rebound was wide. I just decided to get my body out there and it hit me in the ribs so it was good."
He erased the memories of a 5-0 loss in Game 5 at Joe Louis Arena that put the Penguins on the brink of elimination. Pittsburgh returned home and gutted out a 2-1 win, behind Fleury's 25 saves, on Tuesday that forced a seventh game in Detroit.
This was Pittsburgh's second championship in four months, following the Steelers' Super Bowl victory in February.
The Penguins turned the tables on the Red Wings and captured the cup on enemy ice, just as Detroit did in Pittsburgh last year. The Penguins are the first to win the title the year after losing in the finals since Edmonton did it 25 years ago against the New York Islanders - the last finals rematch before this one.
Evgeni Malkin, who led the playoffs with 36 points, earned the Conn Smythe Trophy as the postseason MVP. He assisted on the first of Max Talbot's pair of second-period goals.
Crosby, just four years after being the No. 1 selection in the draft, became the youngest captain of an NHL champion at 21 years old. He played just one shift after leaving the ice during the second period after taking a hard hit along the boards from Johan Franzen.
"It's unbelievable. It's the stuff you dream of as a kid. It's reality now," Crosby said. "We worked so hard. It's amazing to see how far we've come, and couldn't feel any better."
Jonathan Ericsson made it more interesting and tense when he cut the Red Wings' deficit to 2-1 with 6:07 remaining. His shot from inside the blue line sailed past Fleury's glove and sent the fans into a frenzy.
Niklas Kronwall nearly tied it with 2:14 left, but his drive smacked the crossbar and ricocheted out of danger. The Red Wings pressed further in the Penguins end after goalie Chris Osgood was pulled, but the puck ended up behind the net as time ran out.
Pittsburgh had won only once in six games in Detroit in the past two Stanley Cup finals before pulling this one out against the odds. The Penguins' only other victory at "The Joe" was a triple overtime win in Game 5 last year.
The Penguins are the first team since the 2004 Tampa Bay Lightning to win the Cup after trailing the series 3-2 and the first to take Game 7 on the road after the home team won the first six games since the 1971 Montreal Canadiens beat Chicago.
Crosby crumpled against the boards after he was hit and seemed to get his left leg caught. He glided to the bench hunched over and stayed bent at the waist as he was guided to the dressing room 5½ minutes into the period.
He was limited to two shifts, totaling 2 minutes, 39 seconds of ice time in the frame, but his teammates doubled the lead while he was gone. Crosby made it back to the ice midway through the third period for the one shift.
"I just wanted them to keep doing what they were doing," Crosby said of what he told his teammates before the third period. "We did a pretty good job of keeping things away from (Fleury) and he was doing a good job of making saves when he needed to."
Uncharacteristic mistakes by the experience-laden Red Wings led to both Pittsburgh goals.
Malkin, the NHL's leading scorer in the regular season and the playoffs, forced defenseman Brad Stuart into making a bad pass from the right corner. Talbot intercepted the puck and fired it between Osgood's pads at 1:13.
The rest of the Penguins stood tall after Crosby left the ice, and Talbot turned a 2-on-1 into a two-goal lead.
Coach Dan Bylsma became the second coach to win the Stanley Cup with a team he took over in midseason. Bylsma helped rescue the Penguins from a near-playoff miss after replacing Michel Therrien on Feb. 15.
The Red Wings were the overwhelming favorite for the Stanley Cup with four players on the verge of their fifth championship. Detroit had been 11-1 at home in the playoffs.