Sherels' pick came in the first quarter off former Vikings quarterback Tarvaris Jackson, who played his first five seasons in Minnesota.
Donovan McNabb participated in just two series for the Vikings, going 6-of-8 through the air for 81 yards, while Christian Ponder tossed for 63 yards on 6-of-12 passing.
Jackson went 11-of-21 for 75 yards against his former team in the first half.
Charlie Whitehurst entered to start the third quarter and threw for 97 yards and a touchdown on 14-of-19 passing, hooking up with Anthony McCoy on a three-yard TD that pulled Seattle to within 13-7.
The Vikings, however, answered with Tristan Davis' 35-yard TD run in the fourth quarter.