Denver scored first with a 3-yard touchdown pass from John Elway to Gene Lang. San Francisco failed to mount any offense on their first three possessions, gaining a total of only 27 yards. Quarterback Joe Montana was sacked twice, for losses of 9 and 10 yards respectively. They were eventually able to answer with a Ray Wersching field goal in the second quarter. Elway threw a 6-yard touchdown pass to Steve Watson, and a second 49ers field goal attempt was disrupted by fans, leaving the Broncos up 14–3 at halftime.
The 49ers had more success in the third quarter, with a touchdown pass from Montana to Mike Wilson, and a Wersching field goal. They took the lead in the fourth quarter with another field goal, but Rich Karlis' 24-yard field goal with 1:27 left gave Denver a 17–16 victory.
On their last possession of the first half, the 49ers mounted a nine-play drive which ended in a 19-yard field goal attempt. Before holder Matt Cavanaugh received the snap from center, a snowball thrown from the stands landed just in front of him. Distracted, he mishandled the football and was unable to hold it for kicker Ray Wersching. In desperation he picked up the ball and attempted a forward pass, but there were no receivers downfield and it fell incomplete. No penalties or palpably unfair acts were called, and the Broncos took over on downs. They went on to win 17–16, making the failed field goal a pivotal factor.
After the game, referee Jim Tunney explained, "We have no recourse in terms of a foul or to call it on the home team or the fans. There's nothing in the rule book that allows us to do that." He ordered an increase in stadium security at halftime, and no further incidents occurred.