Justin Simmons doesn’t believe in “Fitzmagic.”

The Broncos safety ended any hope of a Dolphins’ (6-4) comeback victory Sunday, coming up with a game-sealing interception in the end zone with 1:10 remaining and giving Denver (4-6) a 20-13 win. It was only 14 plays earlier that Broncos running back Melvin Gordon had fumbled at the 1-yard line, allowing Miami a shot at sending the game into overtime. 

Dolphins backup quarterback Ryan Fitzpatrick — nicknamed “Fitzmagic” for his improbable come-from-behind victories — led the Dolphins down the field 84 yards before Simmons made the play of the game. 

“We’ve got to make a play,” Simmons told the defense on the final drive. “We have to make a sack fumble, couple pass breakups in a row, obviously an interception if we can, but we’ve got to make a play because he’s going to be aggressive.”

3 takeaways from Broncos’ 20-13 win over Dolphins

But it wasn’t Fitzpatrick who the Broncos saw most of the day. It was rookie Tua Tagovailoa, who entered Sunday’s game 3-0 as a starter, before being benched early in the fourth quarter. 

Following a Drew Lock interception on third play of the game, Tagovailoa threw a 3-yard touchdown pass to DeVante Parker. 

But after that? 

Tagovaila was essentially a nonfactor, being sacked four times and hurried seven. He finished the day 11 of 20 for 84 yards and the single touchdown. 

“We have belief in the entire defense,” said outside linebacker Malik Reed, who had four tackles and 1.5 sacks Sunday. “We have belief in each other. To see how we stick together but we never give up on each other. Good, bad, or different — whether things are going good, whether they score, whether we get a pick, whether we get inside someone — to see how we stay together, how we’re happy for each other’s success, I’m glad that’s something that makes our defense special.”

Tagovailoa was replaced by Fitzpatrick with 10:44 left in the game and the Broncos leading 20-10. The Dolphins’ offense seemed to flow much better under Fitzpatrick’s leadership, who finished 12 of 17 for 117 yards and one interception in two possessions. After the game, Dolphins coach Brian Flores said Tagovailoa’s benching was not due to injury as he took a big hit on his final play.

The Broncos — specifically Fangio — knew they’d likely see Fitzpatrick if everything went as planned. Fangio historically has been good against rookie quarterbacks, posting a record of 18-8 as a defensive coordinator and coach when facing a first-year QB. 

“If we played well, they would put (Fitzpatrick) in,” Fangio said. “Tua had only played three games so Fitzpatrick was on a lot of the cut-ups we watched and the film we watched. I watched them myself on the side. I just kind of had a feeling we would see him if we played good.”

The Broncos held the Dolphins to 223 total yards, forcing six sacks and five tackles for loss. Fangio said after the game that they “were thinking to be a little more aggressive than we actually were.”

Still, the Dolphins ran for only 56 yards on a defense that’s been without Von Miller, Mike Purcell, Jurrell Casey and Shelby Harris. The Raiders ran for 203 last week on the same defense.

Guys like Reed, Bradley Chubb, DeShawn Williams, DeMarcus Walker, Slyvester Williams and Dre’Mont Jones all played a huge role for the Broncos. 

“Those guys play hard because they have the opportunity to step up and fill those roles with Shelby being down, with Mike being down,” said Chubb, who had four tackles and a sack. “With DeShawn having two sacks and (Walker) having a sack and (Jones) having a sack and me and Malik — it’s just crazy when you sit back and think about it.” 

Other than Gordon’s late fumble and Lock’s early interception, the Broncos offense played relatively well. Lock was his typical, roller-coaster self, going 18 of 30 for 270 yards and finishing with a 75.7 passer rating. Gordon and Phillip Lindsay combined for 164 yards on the ground with two touchdowns, both by Gordon. 

But it was the defense that won the game for the Broncos. And after arguably its worst defensive performance a week ago in a 37-12 loss to the Raiders, the Broncos played to their full potential. 

“It was just kind of being angry about how last week went down and just know we’re better than that,” said Simmons, who led the team in tackles with seven. “That feeling all week just didn’t sit right and we just knew what we had to do to come out here and beat a really good football team — an offense that moves the ball really well, doesn’t really turn the ball over all that much, a defense that obviously takes the ball away a lot and they play great on special teams. 

“We just knew all week we were capable of winning. We’ve just got to play the type of football we know that we can play.”