The Cardinals were the first side to register points as Chandler Catanzaro converted from 33 yards out to give Arizona a three-point lead in the early stages.
Arizona responded by moving within a point of the opposition when Catanzaro kicked his second field goal in the first quarter from 48 yards.
The Broncos thought they'd moved back ahead in the second quarter, with Manning on hand again to deliver a standout 77-yard pass into the path of Emmanuel Sanders, who latched on only to see the touchdown chalked off as he moved out of bounds.
The decision wasn't to weigh too heavily though, as the Broncos notched the next points when Demaryius Thomas caught hold of a 31-yard Manning pass to push things to 14-6.
Going into the final five minutes of the first half, the Cardinals showed that they weren't in the mood to give things up easily when Andre Ellington completed a five-yard rush.
Denver came back just before the interval, however, as Thomas and Manning paired up again to complete a touchdown from a monstrous 86 yards, leaving the scores at 21-13 going into the break.