Cook's effort helped the Vikings overcome Dak Prescott's performance of 397 passing yards and three touchdowns for the Cowboys (5-4) at AT&T Stadium in Arlington, Texas.
"You saw their guys (Cowboys defenders) getting up slow," Cook told reporters. "Once you get that, it makes you run a little harder."
Vikings quarterback Kirk Cousins completed 23 of 32 passes for 220 yards and two scores in the win. Prescott completed 28 of his 46 attempts and threw an interception. Cowboys wide receiver Amari Cooper had 11 catches for 147 yards and a touchdown. Randall Cobb had six grabs for 106 yards and a score for the Cowboys. The Vikings (7-3) held Cowboys running back Ezekiel Elliott to just 47 rushing yards on 20 carries.
"Dalvin handles everything great," Vikings coach Mike Zimmer said. "He played outstanding. He had some unbelievable runs -- tough, competitive runs -- and a great job on the screens. The offensive line did a great job on those."
Dallas kicker Brett Maher missed a field goal on the Cowboys' opening drive, and the Vikings answered with Cousins hooking up with tight end Kyle Rudolph on a one-yard passing score. Minnesota doubled its lead on their next drive, with Cousins finding Rudolph for another one-yard passing score.
The Cowboys cut the Vikings' lead in half when Prescott found Michael Gallup with a 23-yard passing touchdown in the second quarter. Dallas tied the game on their next drive, with Prescott throwing a touchdown to Cobb. Vikings kicker Dan Bailey converted on a 26-yard attempt to give Minnesota a 17-14 edge at the break.
Bailey made a 27-yard field goal in the third quarter, pushing the Vikings' advantage to six points. Dallas took their first lead of the game on the next drive, with Prescott connecting with Cooper for a 12-yard score.
Minnesota answered with a 13-play, 80-yard scoring drive, with Cook capping the drive with a two-yard rushing touchdown to give the Vikings a 28-21 lead. Maher made a 23-yard kick for the Cowboys at the start of the fourth quarter for the final points of the game. The Vikings punted twice in the fourth quarter and safety Jayron Kearse intercepted Prescott on the final drive of the game.
"It's frustrating," Prescott said. "We had a chance right there at the end, as a quarterback you can't ask for more: the ball in your hands, fourth down and a chance to make a throw to win the game. They made a great play. They made more plays than we did when it counted and beat us situationally."