In 1967 , they became the first AFL team to defeat an NFL team in a pre-season game .
The Broncos competed in the first - ever AFL game and came away with a 13 - 10 victory over the Patriots .
In 1967 , Broncos became the first AFL team to defeat an NFL team in a pre-season game .
The Broncos competed in the first - ever AFL game and came away with a 13 - 10 victory over the Patriots .