Hallander broke a 2-2 tie at 6:50 of the third period when he jammed in Rickard Rakell’s rebound at the left post. Rakell hit the crossbar on a 2-on-1 rush and put the rebound on goal with a backhand shot before Hallander put it in.
Evgeni Malkin, Sidney Crosby and Connor Dewar each scored for the Penguins (3-2-0), and Arturs Silovs made 30 saves. Erik Karlsson and Parker Wotherspoon each had two assists.
Warren Foegele and Kevin Fiala scored for the Kings (1-3-1), who have lost three straight. Anton Forsberg made 22 saves, and captain Anze Kopitar did not play because of a lower-body injury.
Foegele got his first goal of the season to put the Kings up 1-0 at 4:24 of the first period, following up his own rebound with a wrist shot down on one knee from the inside edge of the right circle.
Fiala made it 2-0 at 9:04, finishing off a tic-tac-toe passing play between Quinton Byfield and Joel Armia. After Armia forced a turnover in the Kings zone, he connected with Byfield on the far side, who then sent a centering pass to the front of the net that Fiala tapped in.
After falling behind 2-0 in the first period, the Penguins responded with two goals in 41 seconds in the second period to even the score.
Malkin scored on the power play at 6:37 to cut Pittsburgh’s deficit to 2-1 by putting a wrist shot from the left circle under Forsberg’s glove.
Dewar tied it 2-2 at 7:18, sneaking a shot under the right pad of Forsberg after Noel Acciari chased down a loose puck in transition.
Crosby scored an empty-net goal at 19:29 for the 4-2 final.
Crosby and Kris Letang skated in their 1,000th game together to become the seventh forward-defenseman duo in NHL history to reach the milestone.