The situation: On the opening drive, the Bucs faced a 2nd and 11 on their own 44 with 10:24 left in the first quarter.
The play: Bucs quarterback Mike Glennon ran a play action bootleg, looking for wide receiver Mike Evans isolated on the play.
The result: Cornerback Captain Munnerlyn intercepted Glennon's pass at the Vikings' 15.
How it happened:

The Bucs were in a "12″ personnel set, meaning one running back and two tight ends. They flipped their formation, with both tight ends switching from the left to the right side. Then they motioned tight end Luke Stocker into the backfield to setup an offset "I" formation.
The Vikings were in their base 4-3 defense with Munnerlyn guarding Evans at the top of the play.

The Bucs ran a play action using running back Doug Martin to the weak side of formation. Glennon's main option on this play was Evans, with wide receiver Vincent Jackson cutting across the middle as the second option.
Munnerlyn knew what Evans' route was once he saw the bootleg play.