The score tied the game at 10-10 just before halftime at Mile High Stadium in Denver.
Pittsburgh began the 12-play scoring drive on its own 25-yard-line. The Steelers brought the ball all the way down to the Broncos' 2-yard-line before coming up to a 4th-and-goal. Boswell stepped back like he was going to kick the field goal during the sequence.
But instead of kicking the short field goal, he took a direct snap and stepped to his right. He then tossed a short pass into the end zone, finding the 320-pound tackle for a touchdown.
The Steelers went on to get a 97-yard touchdown from JuJu Smith-Schuster in the third quarter to take a 17-10 lead at the 10 minute mark in the frame.
Boswell also had a 41-yard field goal in the first half for Pittsburgh.