ENGLEWOOD, Colo. -- Entering this season, Denver Broncos cornerback Bryce Callahan talked about rust and the need to get rid of it, to knock it off and leave it behind. For a guy whose 2019 season in Denver was lost to a piece of metal in his foot that bent the wrong way, it seemed fitting.

And while somewhat camouflaged during a 21-point fourth quarter Sunday and a last-second victory led by quarterback Drew Lock, perhaps none of the Broncos' euphoria following a 31-30 win over the Los Angeles Chargers happens without Callahan.

Callahan made the best play of his two-season tenure in Denver with just under two minutes remaining in the third quarter, intercepting Chargers rookie quarterback Justin Herbert. Broncos coach Vic Fangio, who also coached Callahan with the Chicago Bears and has seen every play of Callahan's 52-game career, took it a step further.

"I told him [Sunday] night and again [Monday] that his interception was probably the best play in his career, and I've seen every play in his career," Fangio said this week. "I'm not surprised by it."

Callahan was one of the first players Fangio wanted to acquire just after Fangio was hired to coach the Broncos in January 2019. Callahan arrived with some fanfare and a three-year, $21 million deal. No small thing given the Broncos were also, at the time, having to consider what to do with the contract of longtime cornerback, four-time Pro Bowl selection and No Fly Zone founder Chris Harris Jr.

Then Callahan took an awkward step during a stadium scrimmage in July and another player stepped on his foot. The incident bent a screw that had been inserted to repair a fracture in December 2018. Callahan's first season with the Broncos was over before it had really started.

"I've never had a screw in my foot, but if it's bent, I don't think it's very comfortable," Fangio said. "I know everybody was disappointed that we brought him in last year and he couldn't play, but he was injured."

The Broncos started 0-4, Harris had to play out of position at times to cover for Callahan's absence, and the Chiefs won their eighth and ninth consecutive games against the Broncos by completing any pass they wanted.

The Broncos finished 7-9 -- their fourth consecutive playoff miss -- and Harris departed in free agency after nine seasons with more than a little frustration about how contract negotiations had gone and how he was asked to play in the defense with Callahan out.

Which is why, following an offseason of drive-time criticism, Callahan's interception Sunday meant so much.

"It just took a minute to knock the rust off," Callahan said. "... I feel like each week I get a little more comfortable, I feel a little better. I was frustrated, too, last season, you always want to play ... you always want to make plays."

With the Broncos' offense having spent much of the day in neutral against the Chargers, running back Phillip Lindsay uncorked a 55-yard touchdown run with just over six minutes left in the third quarter to cut the L.A. lead to 24-10. But then Lock threw an interception deep in Broncos' territory.

With the Chargers already in field goal range, Callahan made his move. Herbert tried to find receiver Mike Williams up high, but Callahan beat Williams to the ball, snatching a one-handed interception in the end zone.

"That was a hell of an interception," Broncos safety Justin Simmons said. " ... That changed the whole momentum."

The Broncos scored on their next three possessions, including the winning touchdown on Lock's 1-yard pass to KJ Hamler as time expired.

"[The interception] was huge," Fangio said. "... I knew how he could play if he stayed healthy, and he's proving that this year."

With cornerback A.J. Bouye having missed four games this season because of a shoulder injury and now in the concussion protocol after a collision with teammate Kareem Jackson this past Sunday, Callahan has been the do-it-all player at cornerback. He has lined up outside as well as in the slot and as the Broncos' nickel cornerback when needed.

Fangio has said that Callahan, who largely played in the slot during his four seasons with the Bears, could expand his job description. He has through the first seven games of 2020. He's fifth on the team in tackles, tied for the team lead in interceptions (two) as well as passes defensed.

"I feel like I'm getting into a rhythm," Callahan said. "... Just feeling better and better out there. Comfortable."