Neither team had scored since the first period and it appeared a shootout was on the way. Staal ended that when he ripped a shot past Jonathan Quick for his fourth goal and give the Penguins a needed burst of good news in a tumultuous week.
Penguins captain Sidney Crosby stopped by the morning skate and said there is no timetable for his return from a concussion. The Penguins have been gutted by injury and played four callups plucked from the minors on Thursday morning.
Brett Sterling, one of those callups, scored his first goal for the Penguins.
Jarret Stoll scored for the Kings.
Pittsburgh's Dan Bylsma became the third coach in team history to win 100 games. His .657 winning percentage entering the game was already tops in team history.
He wouldn't have 100 victories in 163 games with this kind of regular lineup.
The Penguins have been devastated by injury and, for now, suspension to a top forward. Crosby remains hopeful he'll return from a concussion and Evgeni Malkin underwent season-ending knee surgery on Thursday morning.
Chris Kunitz is out at least another four to six days, and Mike Comrie, Mark Letestu and Arron Asham are all sidelined with various injuries.
The lost production is staggering: Those six players have combined for 49.7 percent of the Penguins' goals this season (80 of 161).
And the Penguins played the first of four games without left wing Matt Cooke, serving a suspension brought down by the NHL on Wednesday.
Fans brought "Free Matt Cooke" signs in support of the suspended forward.
Without Crosby and Malkin, the offense has fallen into a funk. They scored one goal in their past two games and no player in the lineup scored more than 10 this season.
To fill the lineup, the Penguins recalled four players from Wilkes-Barre/Scranton of the American Hockey League, forwards Ryan Craig, Nick Johnson, Sterling and Joe Vitale.
Sterling wasted no time proving he was the right player for the promotion.
Sterling, from Los Angeles, grew up a diehard Kings fan and dreamed of playing for them. He had to settle for scoring against the Kings, instead, firing the puck over Quick's shoulder for a 1-0 lead.
Johnson assisted on the goal and the fill-ins were on a roll.
The Kings evened the score with 2:43 left in the first. Stoll corralled the loose puck when Penguins defenseman Zbynek Michalek whiffed and put it past Marc-Andre Fleury for his 15th goal of the season.
The Penguins wouldn't escape without an injury - center Dustin Jeffrey left the game in the second period with a lower-body injury.
Crosby surprised his teammates when he stopped by the morning skate. He said he expected to play this season after suffering a concussion, but there are no guarantees he'll be able to make a comeback.
"I'm getting better, it's just slow," Crosby said. "That's the tough part, the progression. Everything is improving, just at a slower rate than I'd want it to be."
Crosby visited the Penguins for the first time since leaving the team last week to visit his parents outside of Halifax, N.S.
Notes: Penguins fans gave a huge ovation when they were asked to "Welcome back to Pittsburgh!" defenseman Rob Scuderi. Scuderi was a member of Pittsburgh's 2009 Stanley Cup champions team and made several key stops to preserve the clinching victory in Game 7. He had 39 points in 300 career games for the Penguins. ... The Kings played their third game in Pittsburgh since October 2003. ... Former Steelers head coach Bill Cowher was at the game.