sentences:  The Steelers were forced to settle for a 36-yard field goal by Jeff Reed to increase their lead to 17–6.On the 49ers' ensuing drive, Alex Smith hit leaping tight end Vernon Davis at the Pittsburgh 5 yard line when he was hit by strong safety Troy Polamalu and flipped into the air.Davis hit the ground, and the ball popped up and was caught by free safety Ryan Clark, who returned it into San Francisco territory.