DENVER » Von Miller tormented the quarterback. Aqib Talib had a pick-six.

Just another Sunday for the Broncos, and after two games, the Denver defense is batting away doubts about whether it could lead the way to a Super Bowl repeat.

The Broncos stifled another contender: This time, it was Andrew Luck and the Indianapolis Colts taking a 34-20 beating.

“I’m pretty sure we woke (critics) up today,” said Broncos linebacker Brandon Marshall, alluding to those who didn’t think the Broncos would be a repeat threat without Peyton Manning, Malik Jackson and a few others who left after last season’s title.

With 1:54 remaining and facing fourth-and-1 at the Indy 17, coach Gary Kubiak elected to kick a field goal to extend the lead to 26-20 rather than try to close out the game with a first down. A risky proposition giving the ball back to Luck, who has picked apart the Broncos (2-0) in recent meetings.

Not so risky this time. On Luck’s first play, Miller got the sack and strip, and Shane Ray returned the fumble 15 yards for a game-sealing TD as the Colts dropped to 0-2.

“If the game is on the line on defense, you can almost guarantee we’re going to finish the game and win it for us,” cornerback Chris Harris Jr. said. “We’ve been in that situation all year last year. Coming into this year, same thing.

“Something we’re accustomed to, we’re used to and we like winning on defense.”

The Broncos rode that defense all the way to a championship a season ago. They think they’re even better at this point, too, than when they went on to led the league in yards per game (283.1).

“We didn’t shut down Andrew Luck at this time last year,” Harris said.

They held Luck to 197 yards passing and came up with the game-changer when Talib stepped in front of Luck’s pass early in the fourth quarter and returned it 46 yards for a score. It was the ninth pick-six of Talib’s career.

Then there’s Miller, who was constantly in the backfield harassing Luck, much like he did last week with Cam Newton on their way to a 21-20 win over Carolina.

“How many sacks did Von have? Five?” Marshall asked.

Only three, actually . But it probably felt like more. After one, Luck said about the only thing he could say to Miller: “good sack.”

“This is what I am supposed to do. That’s what I do. That’s why I dance,” Miller said. “That’s what I live for.”

What else we learned from the Colts-Broncos game:

BUTLER ALMOST DID IT: Cornerback Darius Butler picked off a pass by Trevor Siemian and had a clear path for a TD. All of a sudden, he dropped to the turf with a hamstring injury after a 19-yard return. His afternoon was done. “I’ve never seen anything like it,” Colts coach Chuck Pagano said. “I probably (thought) the same thing that was going through everyone else’s head: ‘It’s a pick-six. No one is going to catch him.’”

ROCKY START: For a third straight season, the Colts start the year 0-2. They rebounded to make the postseason in 2014.

“There is only one level of frustration with losing, and that is, wanting to win,” Luck said.

AILING: Broncos linebacker DeMarcus Ware broke his right forearm early in the third quarter. Kubiak said the team will see Monday morning about the extent of the injury and “whether we think it’s something he can play with or something that has to be fixed.”

IMPRESSIVE SIEMIAN: Siemian completed 22 of 33 passes for 266 and a pick. He also became the fourth Broncos QBs drafted by the team to win his opening two starts. (The others: Marlin Briscoe, Craig Penrose and Brock Osweiler.) “I don’t think you are ever going to be perfect,” Siemian said. “But it’s encouraging we’re doing some good things.”

WRITE THAT CHECK: Safety Darian Stewart was called for a roughing penalty when he hit Luck in the head as the quarterback slid late in the game. “That’s just me playing ball,” Stewart said. “I just hope I’m not fined.” Stewart was docked $18,231 by the league for a helmet-to-helmet hit on Newton in the opener.

TAKING A KNEE: Linebacker Brandon Marshall took a knee again Sunday for the national anthem, but isn’t sure if he will do so again next weekend. “When the time is to stand, then I’ll stand,” he said. Marshall has received plenty of support and criticism over his decision to join San Francisco quarterback Colin Kaepernick and other NFL players in a plea for social change.