Why not? Penguins become first team since 1998 to win consecutive Stanley Cups.

NASHVILLE — The Pittsburgh Penguins’ run to a second straight Stanley Cup started with a question from their coach: “Why not?”

“Everybody’s telling us that we can’t do it,” Coach Mike Sullivan said. “History is telling us that we can’t. All of the experts are telling us we can’t repeat. My challenge to them is, why not?”

With the Penguins on the verge of doing just that entering Game 6 against the Nashville Predators, Sullivan reiterated that message to his team. “Coach drove the point of cementing your own legacy,” forward Chris Kunitz said. No team in the salary cap era had won back-to-back titles, and with Pittsburgh’s 2-0 win over the Predators on Sunday night, the Penguins did just that, becoming the first to repeat since the 1997 and 1998 Detroit Red Wings.

Pittsburgh Penguins captain Sidney Crosby found himself in front of a cellphone screen, posing with teammates for a selfie as he was announced as the Conn Smythe Trophy winner for a second straight year, voted the postseason’s MVP after he finished with eight goals and 19 assists in 24 playoff games. When the moment was appropriately captured, he skated over to collect his latest hardware.

“He’s an elite player, and he’s arguably the best player of his generation,” Sullivan said. “He seems to play his very best when the stakes are high, and this kid just knows how to win.”

A scoreless game through 58-plus minutes tipped in Pittsburgh’s favor when a point shot by Justin Schultz caromed off the end boards as Nashville goaltender Pekka Rinne scrambled back into his net, struggling to locate the puck. It went off the back side of the net, where forward Patric Hornqvist was able to tip it in between Rinne and the post with 1:35 remaining.

Hornqvist had been drafted by the Predators, the last pick in 2005. A 21-goal scorer , he showed what has made the Penguins a Stanley Cup champion for a second straight season, a balanced lineup with timely scoring from an unlikely supporting cast. Struggling in this series with just one point in the first five games, Hornqvist had been playing on a fourth line.

As if to emphasize that point, winger Carl Hagelin, one of the speediest forwards in the league, scored an empty-netter with 13.6 seconds left in the game to secure the result. He, too, had struggled this postseason, joining Hornqvist on the fourth line. His goal that gave the Penguins a 2-0 lead sent the bench into a frenzy, the realization that the repeat bid was imminent.

That Pittsburgh was able to win again is especially remarkable considering its challenging path to the Stanley Cup finals and the injuries the Penguins suffered along the way. Top defenseman Kris Letang didn’t play in the postseason because of a neck injury, leaving Pittsburgh with a blue line lacking star power. Top goaltender Matt Murray missed the first two playoff series with an undisclosed lower-body injury, and in this series, center Nick Bonino has been on crutches with a broken tibia.

Despite that, the Penguins beat the Columbus Blue Jackets and then the Washington Capitals, teams that finished with the best and fourth-best regular season records, in the first two rounds before getting past the Ottawa Senators in the Eastern Conference finals.

“This year, we went in with that expectation that maybe we’d have a legitimate shot at it,” center Matt Cullen said. “But you go through the season with a target on your back, and it’s not easy. To be able to do this, it’s really rewarding.”

Pittsburgh again found success with a balanced forward lineup that leans on its speed and high-end finishing ability. To complement stars Crosby, Evgeni Malkin and Phil Kessel, the Penguins also got significant contributions from unexpected heroes such as rookie forward Jake Guentzel, who had 13 goals and eight assists in the playoffs, and Schultz, who had four goals with nine assists.

The organization is about to enter an offseason of change. Twelve players on the roster are due new contracts, with seven unrestricted free agents. It’s possible that Sunday night’s game was the last of the 40-year-old Cullen’s career. It also probably marked the end of goaltender Marc-Andre Fleury’s Pittsburgh career; with the expansion draft looming this month, Fleury is expected either to waive his no-move clause or be traded so that the Penguins can protect young netminder Murray.

“I don’t know,” Fleury said. “I’ll enjoy tonight and the next few days, and we’ll see.”

Though this series had been close, with the Penguins taking a three-games-to-two lead after their Game 5 win in Pittsburgh, the games themselves haven’t been that competitive. Every game in the series had been decided by at least two goals, with the home team winning every time.

Perhaps the Stanley Cup being in the building Sunday night made for more even play. Neither team had scored through 40 minutes, and the Penguins had a 22-19 edge in shots on goal as both goaltenders shined.

A turning point came early in the second period, when a shot by Filip Forsberg went off Murray, and the referee prematurely blew the whistle, negating a diving poke by Colton Sissons that sent the puck into the net. But the goal was waved off because the whistle had already signaled the play dead, an unfortunate break for the Predators. Halfway through the second period, Murray saved a Sissons breakaway chance.

But with Nashville failing to capitalize on its four power-play chances, including 32 seconds of five-on-three in the third period, the Predators opened the door for the Penguins to take control of the game. Sunday marked the end of an impressive run by the Predators, who finished with the fewest regular season points among playoff teams. A rowdy Bridgestone Arena crowd headed for the exits after chanting “Thank you, Predators.”

Then NHL Commissioner Gary Bettman stepped onto the ice to announce Crosby as the postseason MVP for a second straight season, and the captain proudly skated around with the behemoth trophy, further cementing his legacy just as his coach predicted this team could.