Shane Wright, Vince Dunn and Matty Beniers scored for the Kraken (19-14-7), who have won three straight and are 7-0-1 since a 4-2 loss at Calgary on Dec. 18. Grubauer has won each of his past four starts.
Adam Klapka scored for the Flames (18-20-4), who have lost two in a row after winning their previous three. Dustin Wolf made 23 saves.
Klapka gave Calgary a 1-0 lead off the rush at 6:33 of the first period after Ryan Lomberg’s shot from the left circle hit Grubauer’s left pad and floated to Klapka, who was skating in down the slot. Klapka batted the puck out of the air and under Grubauer’s glove.
Jacob Melanson tied it 1-1 at 2:17 of the second period with his first NHL goal. Ryan Winterton got his own rebound at the bottom of the right circle and sent a cross-crease pass backdoor to Melanson, who one-timed it into an open net behind Wolf.
Seattle then scored four straight goals in the third period.
Wright gave the Kraken a 2-1 lead at 1:57 off a 2-on-1 rush, hustling to the top of the crease and redirecting Ben Meyers’ saucer pass under Wolf’s right arm.
Dunn extended it to 3-1 at 5:12, taking Kaapo Kakko’s feed from the right half wall and snapping a shot from the slot past Wolf’s glove.
Freddy Gaudreau scored an empty-net goal to make it 4-1 at 17:25, and Matty Beniers found a Jared McCann rebound and slipped it through Wolf’s five-hole at 17:39 for the 5-1 final.