ORCHARD PARK, N.Y. — They were told it was a trap game. That after impressive victories at home, against the Los Angeles Chargers and then the Dallas Cowboys, that they would have a tough time at Buffalo, which had been unimpressive.

The Broncos did.

The same Denver team that contained Chargers quarterback Philip Rivers and shut down Cowboys running back Ezekiel Elliott was felled by costly turnovers and penalties in a 26-16 loss Sunday.

Broncos quarterback Trevor Siemian completed 24-of-40 passes for 259 yards but was sacked three times and had two second-half interceptions that Buffalo capitalized on, along with Denver penalties, to pull away.

"We talked about, to win a road game, you've got to be great in the red zone, great with the turnovers and great on third down, and those things we didn't do," Broncos head coach Vance Joseph said. "Their last drive, they converted I think three or four great third downs. We had two turnovers on offense. We didn't play the critical parts of the game well today, so we didn't win the football game, bottom line."

The Broncos' defense came out swinging with a pair of first-quarter sacks, one by Von Miller and another by fellow linebacker Brandon Marshall, and yielded only 10 net yards. But Denver's defense struggled to clean up the offense's myriad miscues the rest of the day.

Joseph said he saw what he expected all along. He expected a stout defensive seven, and the Bills showed one. He expected running back LeSean McCoy to get his yards, and he did -- 21 rushing and 48 receiving. He expected quarterback Tyrod Taylor to be able to make plays with his arm and his feet. He did: 231 yards passing, two touchdowns and 13 yards rushing.

Denver could not keep pace, hurt badly by going 1-of-3 in the red zone and its flurry of mistakes.

"You've got to come out and play your game," said Broncos wide receiver Demaryius Thomas, who had six catches for 98 yards. "You have to come out and be your best every week. And I don't think we were the better team today, and that's why they got the win."

The Broncos got on the board first when Siemian engineered a 12-play, 53-yard drive that was aided by a pair of defensive pass interference calls and capped by a 38-yard field goal by Brandon McManus.

BOX SCORE: Bills 26, Broncos 16

Buffalo responded with a nine-yard touchdown catch by Andre Holmes, but a string of defensive penalties by the Bills helped Denver quickly reclaim the lead. A 32-yard run by running back C.J. Anderson was extended 15 yards because of an unnecessary roughness penalty by Bills safety Micah Hyde, and an incomplete pass by Siemian was given a do-over after a roughing-the-passer penalty by defensive end Jerry Hughes. On the next play, running back Jamaal Charles waltzed into the end zone for a 12-yard score -- his first as a Bronco.

But flags that held back the Bills early began doing the same to the Broncos. There was an illegal formation penalty on a Broncos punt that cost them 37 yards of field position in the second quarter, which led to a 49-yard field goal by Steven Haushka, which made it 10-10.

The Broncos' defense was gashed late in the second quarter as it allowed Buffalo to cover 38 yards in 41 seconds to set up Hauschka's 55-yard, game-tying field goal, making it 13-13 at the half.

In the third quarter, Taylor came alive and picked up 56 yards on a pair of deep passes, then found tight end Charles Clay in the end zone for a go-ahead touchdown, making it 20-16.

Field position killed the Broncos. So did penalties. So did critical turnovers and questionable decisions.

A fake Broncos punt at the end of the third quarter -- running back De'Angelo Henderson was tackled for a gain of 1 yard when he needed two -- set up the Bills at Denver's 31. Hauschka hit a 53-yard field goal to extend the Bills' lead to 23-16.

"It's a call from the sideline, and if we have the look we want, we run it. A look was there," Joseph said. "We had a late sub on the field so we kind of gave them time to adjust. It didn't work, but in my opinion, it was the perfect timing, it was a good call, and the look was there. We had our offensive line versus their punt return team, which is big skilled players and it was fourth-and-2 so we took a chance."

The mistakes continued to game's end. Thomas was flagged on a pick play, and then Buffalo's Adolphus Washington was penalized for illegal hands to the face on a third down, giving Denver a golden opportunity to bounce back.

But Siemian, on a pass intended for Bennie Fowler, threw his second interception of day on a first down at Buffalo's 24-yard line.

"I thought he was going in and he was going out," Siemian said of Fowler. "But, again, I'm responsible for every ball that goes in the air. Can't do that back there. Can't turn it over anywhere when we're backed up like that. You can't do that."

The final dagger: Miller being flagged for unsportsmanlike conduct on a Bills third-and-6 when he extended his hand to help up Taylor after a hit, then quickly pulled it back. The play gave Buffalo 15 yards and a first down as it marched down field for a late field goal that sealed the win.

The questionable call was the lone blemish for Miller, who was a one-man wrecking crew with six total pressures (one sack, hit quarterback hit, four hurries) on only 28 pass rush snaps, according to Pro Football Focus.

"I can't put my team in situations like that," Miller said. "I've brought us home 50 million times. I've closed games 50 million times. I got to be smarter than that. I'm always on the rookies and the all the young guys about being smart and doing this and doing that, and I go out there and do something like that, in a crucial situation in a game. I've just got to be better than that.

"One thing about it, I'm always able to bounce back. I always learn from my mistakes. I just can't kill us -- I killed the game today."

The Broncos got trapped. Or maybe, on this day, they just weren't the better team.