Nazem Kadri scored, and Jacob Markstrom made 19 saves for the Flames (14-16-5), who have lost consecutive games after winning three straight.
"I think obviously right now the mood's not top, but we'll come in tomorrow ready to work again and we'll keep pushing ourselves to get over that hump, get over that .500 mark, and push ourselves into a wild card spot," Calgary captain Mikael Backlund said.
Wennberg put Seattle up 2-1 at 6:00 of the third period with a shot short side over Markstrom's right shoulder from the face-off dot.
"It's a great play," Wennberg said. "I feel like it was opening up. It was a great sauce pass. I feel like [Brandon Tanev] was open on the back, so I think the goalie was cheating a little bit on it. I didn't really see where it went but happy with the result for sure."
The goal came after Driedger stopped Yegor Sharangovich in the slot 33 seconds into the third and made a glove save on Martin Pospisil's backhand on a drive to the net at 1:48.
Driedger also stopped Elias Lindholm at the edge of the crease with 16 seconds remaining to preserve his first NHL win since April 29, 2022.
"I think you try to bear down on those situations," Kadri said. "Of course, we want to score and capitalize on those opportunities, but at the same time, he made some great saves, timely saves to keep his team in it on the road. We certainly pushed."
Yamamoto gave the Kraken a 1-0 lead at 2:24 of the first period on the Kraken's first shot, a wrist shot that beat Markstrom low blocker side on a breakaway created by a stretch pass from Vince Dunn.