Beniers, who had nine points (three goals, six assists) in 10 NHL games last season, gave the Kraken a 1-0 lead at 2:12 of the second period.
Martin Jones stopped all 13 shots he faced in 32:15, and Joey Daccord made 15 saves in relief for Seattle in its first preseason game.
Olivier Rodrigue started in goal for Edmonton and allowed one goal on nine shots in 30:00. Ryan Fanti made 16 saves in relief.
Ryan Donato made it 2-0 at 14:15 of the second, and Morgan Geekie scored shorthanded 43 seconds into the third period for the 3-0 final.
