Harris -- who spent five seasons with the Broncos -- was doing a postgame interview when he made it clear he hasn't forgotten about being shipped off to Seattle to make room for Russ in Denver.

"That's what happens when you trade one of your D-linemen to the other team," Harris told NFL Network reporter James Palmer. "We sit here and make plays, all of us. That's what happens when you get two goal-line stops, right there, a win. Can't draw it up any better than that, man."

You'll recall ... Russ was traded from the Seahawks to the Broncos in March in exchange for Harris, Drew Lock, Noah Fant and some first- and second-rounders in the upcoming drafts.

Harris admitted he had some extra motivation playing against his former team and their new $245 million man ... and took joy in knocking off Russ, who was booed heavily in his return to Lumen Field.

"We come out here, everyone doubted us, everyone made this about Russ," Harris added. "We made about the Seattle Seahawks. We came out here, played good ball for four quarters, come out with the W."

"Nobody expected us to win except for us. It’s always going to be us," he continued.

Shelby is right -- the Seahawks, led by Russ' former backup Geno Smith, were massive underdogs against the Broncos.

In the end, a questionable decision by rookie head coach Nathaniel Hackett to attempt a 64-yard field goal instead of going for it on 4th and 5th cost the Broncos the game.