It was always going to be Broncos vs. Patriots

You knew it was going to come to this, Patriots fans. It was written with the Sharpie of destiny. Peyton Manning and the Denver Broncos would be the final barrier for Tom Brady, Bill Belichick, and the unsinkable Patriots on the road to the Super Bowl.

The Patriots and Broncos are the last teams standing in the AFC, after the top-seeded Broncos survived a late San Diego Chargers comeback to score a 24-17 victory on Sunday at Sports Authority Field at Mile High.

Brady-Manning XV, otherwise known as the AFC Championship game, will determine who represents the AFC in Super Bowl XLVIII. It will take place Sunday at 3 p.m. in Denver, but the countdown to the final showdown has really been on all season.

Like Pepsi vs. Coke, BMW vs. Mercedes, Apple vs. Google, Brady vs. Manning represents an on-going struggle for supremacy between the two biggest brand names in the genre, the genres being erudite, iconic franchise quarterbacks.

That show “Intelligence” about the guy with a computer chip in his brain that CBS kept annoyingly pumping during Sunday’s Broncos-Chargers game would be less far-fetched if it was about Brady or Manning and their command and recall at the line of scrimmage.

It will be the third time that Brady and Manning have met in the AFC Championship game and the fourth time in the postseason overall, with Brady holding a 2-1 lead.

However, each has won an AFC title against the other on his home field. Brady and the Patriots won the 2003 AFC Championship at Gillette Stadium. As a member of the Colts, Manning helped his team rally from a 21-3 deficit to break the hearts of the Patriots in the 2006 AFC title game inside a sweltering RCA Dome in Indianapolis.

In that 2006 AFC Championship game, played in January of 2007, it felt like the Patriots had sent Brady into a gunfight with a Super Soaker. The eyes of Dr. T.J. Eckleburg from “The Great Gatsby” had nothing on the eyes of Reche Caldwell.

This matchup could have a similar feel, as Manning spent this season bumping Brady and the 2007 Patriots out of the record books.

Manning threw for an NFL season-record 55 touchdowns, breaking Brady’s mark of 50, and he also set the season record for passing yardage (5,477). The Broncos broke the 2007 Patriots’ record point total of 589 by scoring a staggering 606 points. Denver became the first team to have five players register double-digit touchdowns.

This is Manning’s modus operandi, piling up stats and points in the regular season.

Meanwhile, Brady, stripped of his weapons because of injury, incarceration, inexperience, and financial intransigence, threw for his fewest TD passes (25) since ’06.

TB12 has taken a back seat to LeGarrette Blount and the Patriots’ running game the last three weeks. Brady hasn’t passed for 200 yards in any of the Patriots’ last three games, including their 43-22 trampling of Manning’s old team, the Colts, on Saturday night in an AFC divisional game.

In their last three games, the Patriots have morphed into Tom Osborne’s Nebraska teams, averaging 214.3 yards rushing per game. (That fits right in with Manning’s incessant “Omaha” calls at the line of scrimmage.)

In case you’re wondering, Denver tied with Seattle for the seventh-best run defense in the NFL this year. The Broncos quickly derailed the Chargers’ plan to run them out of the playoffs.

The quarterback comparison is the sexy subplot of the game, but the determining factor will be what it’s always been — not Brady vs. Manning, but Manning vs. Belichick.

This will be the ultimate test for the Hoodie and a defense that has withstood a rash of injuries to vital defensive players — taking down Manning and an offense so high-powered it should have a National Rifle Association lobbyist.

Aided by a frosty, gusty New England night, the Patriots held Manning to his lowest completion percentage and yardage production of the season in the teams’ meeting Nov. 24.

Manning was 19 of 36 for 150 yards with two touchdowns and an interception as the Patriots dared Denver to run. The Broncos obliged and ran for 280 yards on 48 carries, but surrendered a 24-0 lead, as Brady rallied the Patriots for a 34-31 overtime win and the largest comeback in franchise history.

That bumped Brady’s record against Manning to 10-4 and Belichick’s to 11-6.

This game isn’t just about opportunity now; it’s about legacy as well.

Beating Manning on his home turf with a depleted offensive arsenal and an injury-ravaged defense would be one of the great feats of Belichick’s esteemed football career.

The Patriots have placed 11 players on injured reserve this season, including six starters, four of them on defense. Their best offensive weapon right now, Blount, was acquired for a seventh-round pick and an Olympic sprinter who was noncommittal about football.

Manning is 10-11 all time in the playoffs. Getting to .500 in postseason play by beating his New England nemeses of Brady and Belichick in the AFC title game would burnish a playoff résumé that doesn’t have the same luster as Manning’s regular-season résumé.

Adding to the intrigue is that Manning has Brady’s BFF and former favorite target, Wes Welker, on his side. Welker couldn’t come to a contract agreement with the Patriots after he overplayed his hand and the Patriots undervalued him. He ended up at Manning’s side in Denver.

After missing time with a concussion, he returned against the Chargers Sunday and caught six passes for 38 yards and a touchdown.

Welker said it himself, it’s kind of nice to stick it in Bill’s face.

He’ll have his chance.

Patriots-Broncos. The AFC championship couldn’t have come down to two other teams or two other quarterbacks. It always felt like the only way to go.