PITTSBURGH -- Martin Jones' biggest save of all for the San Jose Sharks was the series.

Jones turned aside a flurry of Penguins shots during a frantic but scoreless final two periods in a potential clinching game for Pittsburgh and the Sharks kept the Stanley Cup finals going, winning 4-2 in Game 5 on Thursday night.

"We needed big game performances ...and he (Jones) was fantastic," Sharks coach Peter DeBoer said. "We found a way to stay alive."

With nearly 19,000 jammed inside Consol Energy Center, and probably twice that jammed into two downtown Pittsburgh viewing locations, the confident Penguins were poised to be the first major sports team to clinch a title in the city since the 1960 Pirates.

But Melker Karlsson scored what proved to be the winning goal at the end of a five-game breakout in the first period, and Jones -- with his strongest game of the finals yet -- made the lead hold up despite the Penguins' overwhelming 46-21 edge in shots. The 46 shots were a Penguins record in a regulation playoff loss.

"Obviously you never want to see a celebration throughout a city -- it would be a long bus ride back to the hotel," Sharks center Chris Tierney said. "When you're in a do-or-die situation, everybody brings their game up a level and everybody plays desperate."

Now it's the Penguins who will be a bit desperate -- to avoid a Game 7 -- as they hold a 3-2 series lead heading into San Jose for Game 6 on Sunday.

"They're going to show up for Game 6 -- and so are we," Sharks forward Joe Thornton said.

Game 5 started going the Sharks' way -- disappointing one of the loudest home crowds in Penguins history -- almost from the start.

"We came in a little bit earlier (to the arena), but we saw it," Thornton said of the thousands of fans who began lining up outside an arena video screen eight hours before the opening faceoff. "But we just know if we lose, we go home."

Brent Burns and Logan Couture scored their first goals of the finals only 1:49 apart early in the first, and the Sharks stood up to a Penguins comeback on which Evgeni Malkin and Carl Hagelin scored in a span of 22 seconds.

Karlsson scored off Couture's adept backhand pass at 14:47 of the first, and there was no more scoring under Joe Pavelski scored his first goal of the finals into an empty net with 1:20 remaining.

Even with '60 Series star Bill Mazeroski twirling a yellow Penguins towel, the Sharks spoiled a denied the Penguins a fourth Stanley Cup in 25 years and a second in seven years.

"You want to close it out, but like any playoff game you've got to turn the page," Penguins captain Sidney Crosby said.

Coach Mike Sullivan's explanation: "I thought the team as a whole was a little bit unsettled at the first part of the game."

They looked it, too.

Jones and Penguins goalie Matt Murray each looked uneasy at the start, but it was Jones who made more -- and much tougher saves -- the rest of the way, as Pittsburgh pressed but never scored the tying goal. Jones finished with 44 saves -- the most in a finals win since 1968 for a goalie whose team was facing elimination, according to Elias Sports Bureau.

"That was unbelievable," Sharks defenseman Justin Braun said. "He doesn't flinch (when players crowd the net), he doesn't go after guys, he doesn't lose his cool. He's popping us on the pads, saying we're doing a good job when usually it's him bailing us out."

After a succession of low-scoring games -- the winning team never scored more than three goals in the first four games -- this one started out as a shootout.

San Jose scoring the first two goals in a span of 1:49 early in the first. That was more goals than Murray gave up in three of the first four games -- and the Sharks' first lead in any regulation in any game.

"It's going to be hard to win in the finals, and I thought we played a really good game -- except for the first five minutes," Penguins forward Patric Hornqvist said.

The Penguins surged back with a power-play goal by Malkin less than two minutes after the Sharks made it 2-0 then, even before that goal announcement was made, Hagelin tied it 22 seconds later.

With Murray playing shakily early, the Sharks retook the lead at 3-2. Karlsson wristed a shot under Murray's glove at 14:47 off Couture's perfectly placed backhand pass.

The goals came quickly at the start -- probably much faster than either team expected.

Karlsson's forechecking kept the puck in the Penguins' end, Burns brought it around from behind the net and beat Murray high to the short side 1:04 into the game for his seventh of the playoffs. Couture followed at 2:53 with his ninth, redirecting defenseman Justin Braun's shot from the point.

But rather than being stunned into submission, the Penguins came right back with Malkin scoring his sixth and second in as many games at 4:44 with a shot that deflected off Braun's stick and past Jones. Malkin's 22 playoff power-play goals since 2007 lead the NHL.

The Penguins, mere seconds after the ensuing faceoff, regained the puck on Sharks defenseman Brenden Dillon's giveaway and Hagelin tipped in Nick Bonino's shot for his sixth at 5:06.

NOTES: The Penguins' previous record for shots in a regulation playoff loss was 41, against New Jersey in 1991. ... The Penguins had never before lost a potential Stanley Cup-clinching game. ... Sharks LW Tomas Hertl (six goals, five assists in 20 playoff games), San Jose's best player in the first two games in Pittsburgh, missed a third consecutive game with a lower-body injury. ... Pittsburgh had won five straight games in the finals at home. ... Since 2007, Sidney Crosby's first playoff year, Phil Kessel and Marian Hossa (2008) are the only Penguins players other than Evgeni Malkin and Crosby to have 10 goals and 10 assists in a postseason.