Just 57 seconds into the game, Aston Villa were ahead. Gabriel Agbonlahor accelerated down the left wing and pulled the ball back to Marc Albrighton from the byline. The winger stepped over the ball and left it for Westwood, who fired home his second goal of the season from the edge of the box.
Agbonlahor had a chance of his own 10 minutes later, but it cannoned off a Hull defender to deflect behind for a corner.
Four minutes before half time, Nathan Baker was denied but Weimann followed up to lash the ball home, and the Austrian forward netted again in first-half stoppage time to put breathing space between Villa and Hull.