DENVER—The first sign of trouble was when the line of busses carrying New York Giants into the bowels of eventually-to-be-renamed Sports Authority Field at Mile High.

The way everyone around here talked about the game this week between the 3-1 Broncos and banged-up, malcontent, 0-5 Giants, you half expected the New York football team to stay at home and call the whole thing off.

The Giants not only showed up, they whipped the Broncos before going into a protective shell and settling for a 23-10 win upset win on an otherwise pleasantly cool Sunday evening in mid-October. And it wasn't that close. The Giants were up 20-3 with 5 minutes remaining.

"They kicked our (butt) tonight, plain and simple,'' said Broncos' running back C.J. Anderson, who was held to 17 yards on nine carries -- but no yards on a fourth-and-goal carry from the 1 midway through the fourth quarter that essentially clinched the win for the Giants. "Bad execution, bad football. We played terrible. We played terrible in all phases of the offense. I played terrible personally. You can't expect to walk on the field and think you're going to win a football game.''

The Giants were so bad, the Broncos were not only supposed to win, but name their score.

The Giants were so bad at 0-5, with their top four receivers, including Odell Beckham Jr., were out with injuries, with their well-paid cornerback Dominique Rodgers-Cromartie suspended for insubordination, the 3-1 Broncos entered this game as a whopping 12-point favorite.

"It didn't worry me. I knew it was going to be a tough out,'' said Broncos head coach Vance Joseph. "That defense is a really good defense. That was my concern.''

It may have been the Broncos worst night in years. Not only did they get drubbed by a heretofore winless opponent, the Broncos suffered what appeared to be serious injuries to receivers Emmanuel Sanders and Isaiah McKenzie. Maybe they weren't as bad as they looked. X-rays for both players were negative, although neither player was cleared as both will undergo MRI exams Monday morning.

For a moment it appeared to get even worse for the Broncos as quarterback Trevor Siemian left the game late in the first half after re-injuring his left shoulder while trying to make a futile tackle attempt on a Janoris Jenkins' interception for a touchdown. After backup quarterback Brock Osweiler took the final 48-second possession of the first half, Siemian returned to play the entire second half.

“I tried to tackle the guy and that’s certainly not my specialty,'' said Siemian, who was 29 of 50 for 376 yards with a late touchdown pass to Jeff Heuerman, but also threw two interceptions. "I’m fine. A little sore, but I’m fine.”

Joseph said after the game he wasn't sure how serious Siemian's left shoulder injury is and more would be known following tests Monday.

Let’s get it out there: The bye came at a bad time for the Broncos. They looked like a top AFC team going in. They got crushed by one of the worst NFC teams coming out.

"We just can't have this lackluster performance again,'' said Broncos' inside linebacker Brandon Marshall. "I know everybody is going to be ready for next week in L.A., but we came out flat and couldn't stop the run and couldn't run the ball.''

Since Marshall brought it up, the pain of losing to the no-longer hapless Giants stings more given the Broncos' upcoming schedule. In the next four weeks, the Broncos play three consecutive road games at the Chargers, who have won two in a row, at 5-1 Kansas City and at 5-1 Philadelphia. Then the Broncos finally get to return home and play the defending Super Bowl-champion New England Patriots.

In other words, the Broncos just blew it.

The Broncos had been heavy favorites like this plenty of times before but not in three years. And not since someone named Peyton Manning was their quarterback. For this game, Peyton watched from a suite as his younger brother Eli Manning played quarterback for the Giants.

Siemian was the Broncos’ quarterback and he not only generated just 10 points against a Giants’ defense that entered the game ranked 26th in the league, he threw two interceptions. His last throw of the first half was intercepted by Jenkins, who returned it 43 yards for a touchdown.

That pick six put the Giants up 17-3 with 48 seconds remaining in the half. Siemian came up favoring his left shoulder while diving in a futile attempt to tackle Jenkins. It’s the same shoulder Siemian hurt last season and eventually needed surgery to repair.

The Broncos put in backup quarterback Brock Osweiler for the final 48 seconds of the half, but after completing his first pass to Bennie Fowler for 9 yards, the hurry up possession would eventually end in a kneel down.

The crowd of 75,174 booed their team into the halftime locker room.

Siemian came back to play the second half, but a Demaryius Thomas fumble thwarted one promising drive, Brandon McManus had a field goal blocked -- his second failed attempt of the game-- and the Broncos had one possession end at the Giants' half-yard line when Anderson was stacked up on fourth-and-goal from the 1.

For starters, it appeared the Broncos were suffering from the bye-week blues. Their timing was a tad off and their offense began with back-to-back series of three-and-outs.

Meanwhile, Eli Manning and the Giants predictably used their first-round rookie tight end Evan Engram and running backs to march down the field against the supposedly vaunted Denver defense. The Giants had a 13-play drive that at one time reached first and goal at the 8 before they stalled and settled for a short Aldrick Rosas field goal and a 3-0 lead.

“We knew we were going to have to run it and keep running it and stick with it. I thought the guys did a nice job. I hit [Tight End] Evan [Engram] with a couple shallow routes and got some big gains. Right off the get go, I thought it was a great start to the game. Defense gets the three and out and we get the ball drive down there. Headed south for the field goal there but, just moving the ball and saying, ‘Hey, We’re going to be competing.’ I’m proud of the guys for the way they competed. We had a chance to close out the game and we did it.”

The Broncos could have come back and tied it thanks to a 33-yard pass play from Siemian to Sanders, but McManus’ kicking slump continued as he missed a 35-yard field goal.

McManus has now missed four field goal attempts this year, and had another one blocked.

"You just can't miss a field goal like that and set the tone for the game,'' McManus said. "It hurts a lot of people to have a good drive like that, get down the field and then you miss a short one.''

The Giants came back on their next drive with two big plays. The first was a third-and-10 play that Manning picked up with a 15-yard completion to Roger Lewis Jr. On the next play, running Orleans Darkwa burst off left guard and through a huge hole for a 47-yard gain to the Broncos’ 13. After holding down the likes of Ezekiel Elliott to 8 yards on nine carries and Marshawn Lynch to 12 yards on nine carries, Darkwa slashed the Denver D for 117 yards on 21 carries.

Three plays later, Manning rolled right and hit Engram, who ran a sideline rub route to the pylon that beat safety Justin Simmons for a touchdown and a 10-0 Giants lead.

The Broncos’ comeback was through Demaryius Thomas. He had a huge first half, catching six passes for 79 yards. But on first and goal from the Giants 10, Siemian threw three incomplete passes and the Broncos settled for a 30-yard field goal attempt. This time, McManus was true. It was 10-3 Giants.

The game's biggest play, though, came with 1:01 left in the half. The Broncos were facing third-and-10 when Siemian from his own 38 threw a sideline pass intended for Bennie Fowler III. Jenkins saw it, jumped it, caught it, and returned it for a back-breaking, 17-3 lead.

"We were talking about it on the sideline that he was going to lock on and stare down the receiver,'' Jenkins said.

“I thought the intensity was fine, I think we hurt ourselves, right?'' Siemian said. "I mean we didn’t score in the red zone and I turned it over. It’s tough to win that way. You’re already playing a good team; you can’t play against yourself as well.”

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