They also entered Sunday Night Football with an unspoken mission: break the record. The all-time passing touchdown record.
Manning needed three.
Touchdown 507 was the first for Emmanuel Sanders in a Denver Broncos uniform, a speedy quick three-yard out. One down. Two to go.
Touchdown 508 was a thrilling yards-after-the-catch bullet from Manning to Wes Welker, who dove for the pylon for the score. Two down. Record tied. One to go.
Touchdown 509. The record-breaker. The most career TD passes by a quarterback in NFL history. Manning hit - who else? - Demaryius Thomas for the eight-yard touchdown, giving the Broncos a 21-7 lead.
And that was just the first half.
Manning would add Touchdown 510 - a 40-yard bomb down the seam in the third quarter - before Ronnie Hillman added two rushing touchdowns to give the Broncos a dominating 42-10 lead. The rout was on into the fourth quarter when the Broncos rested Manning in favor of Brock Osweiler (the Broncos play the San Diego Chargers Thursday night).
Denver's defense was just as impressive. Broncos defenders swarmed Colin Kaepernick, who started the game with some accurate fire that ultimately sizzles. He was sacked six times - thrice by DeMarcus Ware, who was bench-pressing Joe Staley, twice by Von Miller, and once by Malik Jackson. Aqib Talib added an interception in what was an incredible, complete team win for the 2014 Broncos - easily their best game to date.
This might have been the best regular season game in Denver's Peyton Manning era.
Manning finished 22 of 26 for 318 yards, four touchdowns, no interceptions, a near-perfect 157.2 pass rating, and an all-time NFL record. Demaryius Thomas continued his dominant comeback (don't call it a comeback) with 171 receiving yards on the night. The Broncos rushed for 117 yards, including 74 from Hillman with a 5.3 average.
The Broncos played one of the NFC's best - a team that Richard Sherman basically said should have been in the Super Bowl instead of the Broncos a year ago - and went for the throat.
They'll need that same killer instinct Thursday against the Chargers.