The Vikings finally found their quarterback for 2013 and their defense rediscovered its backbone.

Matt Cassel threw a pair of touchdown passes to Greg Jennings and Adrian Peterson's 60-yard scoring run highlighted a 140-yard two-TD performance as Minnesota used a balanced offense and ferocious pass rush Sunday to survive for a 34-27 victory over the Pittsburgh Steelers in front of 83518 fans at Wembley Stadium.

But it was the defense that ultimately won the game.

On the field for the third straight week with a lead to preserve in the final two minutes the Vikings were marched by the Steelers' wily quarterback Ben Roethlisberger back to their 6-yard line with 22 seconds remaining.

However the unit stiffened as Everson Griffen and Chad Greenway doubled-teamed to sack Roethlisberger and force a fumble that Kevin Williams recovered with eight seconds left.

Cassel starting his first game in place of the injured Christian Ponder seized the moment by delivering Minnesota's first victory of the season and more than likely secured the No. 1 job when the Vikings (1-3) return from their bye to play host to the Carolina Panthers Oct. 13 at the Metrodome.

He was poised and precise when he needed to be completing 16 of 25 passes for 248 yards finding a favorite target in wideout Jerome Simpson (seven catches 124 yards). Most important there were no turnovers. And Cassel also had Simpson to be thankful for that.

The receiver recovered a Cassel fumble near midfield to extend Minnesota's final field goal drive of the first half.

The Vikings' defensive line and front seven dominated the Steelers' maligned offensive line sacking Pittsburgh quarterback Ben Roethlisberger five times and intercepting him once (Chad Greenway). Jared Allen led the attack with 2-1/2 sacks.