Two turnovers created by Marcus Peters (and three by the Chiefs in the half) had the Denver Broncos trailing Kansas City 17-3 at halftime of their “Monday Night Football” showdown at Arrowhead Stadium.

Peters forced a fumble and intercepted Trevor Siemian, both in the first quarter, with the fumble leading to a scoop-and-score for the All-Pro defensive back.

Things were rocky for Siemian and the Denver offense in the first half. His first ‘completed’ pass of the game, in Denver’s fourth possession, was to Peters. It was that kind of half for Siemian, who went to the locker room with an 8.9 passer rating after completing just five of 14 passes for 56 yards.

Siemian missed Bennie Fowler low and away on second-and-five on the game’s opening possession. Then Fowler and Siemian appeared to have their signals crossed on third down in the same area and it was a quick three-and-out for the Broncos to start the game.

The dangerous Tyreek Hill got loose on a short kick by Riley Dixon, returning the ball back across the 50 and into Denver territory, but a hold against Kansas City sent the Chiefs back to their own 18-yard line for their first possession.

Tight end Travis Kelce found some open space in the middle of the field between Denver’s cornerbacks and safeties to convert a third down for 19 yards. The KC offense stalled out from there. The gusty wind at Arrowhead yielded only a 31-yard punt by Dustin Colquitt and the Broncos took over at their own 27.

In his first touch in his old stadium, former Chiefs running back Jamaal Charles broke an impressive run off right guard for an 18-yard pickup to give Denver a spark. That spark would blow up in Charles’ face two plays later. After another gain of four, Charles got the call again only to have the ball knocked free by Marcus Peters, who picked up the fumble and took it 45 yards for a touchdown and an early Chiefs lead.

C.J. Anderson failed to get anything going in the run game on the Broncos’ ensuing possession before Trevor Siemian skipped a third-down pass short of A.J. Derby and the Broncos were again forced to punt.

Kansas City was handed another big momentum swing on third-and-two on the next series when Justin Simmons was flagged for targeting, coming in high on Demarcus Robinson. A potential three-and-out turned into a 68-yard touchdown drive after Alex Smith found Kelce twice. The first, a screen, went 16 yards. Then, Smith hit Kelce wide open en route to the end zone with Darian Stewart in coverage and Denver was deep in a 14-0 hole before Siemian had even completed a pass.

Siemian’s first caught pass of the evening went to Peters, who turned the corner on Jeff Heuerman running a go route for an easy interception and Peters’ second forced turnover of the quarter.

With momentum fully in their favor, the Chiefs tried to get fancy after the turnover. On second-and-goal from the 9-yard line, Andy Reid called a gadget play that called for Tyreek Hill to throw the ball into the end zone after taking a sweep toss to the left edge. The Broncos had the play blanketed, though, and Darian Stewart intercepted the ball in the end zone to prevent Kansas City from going up three scores.

The Broncos finally got the chains moving on their fifth drive, with Siemian finally finding a man in his same colors on the first play of the ensuing drive. He connected with Demaryius Thomas to get things going. Anderson and Charles combined for 29 yards on the drive to get the ball into Kansas City territory. Virgil Green picked up a a big third-and-one with a 16-yard catch and run to get Denver into a goal-to-go situation. Two negative plays, including a sack of Siemian on second down, eventually resulted in a Brandon McManus field goal and Denver had their first points since the fourth quarter of their loss to New York in Week 6. It was a 71-yard drive that took 7:07 off the clock.

The Denver defense forced a quick three-and-out and the offense took over at their own 19 badly needing another lengthy scoring drive.

It wouldn’t come, though, as Green dropped a pass right into his hands on second down and Siemian was bowled over trying to find Thomas on the outside on third down. A false start penalty on the punt backed Denver up to the 17 and a 37-yard Riley Dixon punt gave the Chiefs the ball at their own 46.

Smith hit Kareem Hunt on the first play of the drive, then Hill on the second play for a cumulative gain of 37 yards to put the Broncos’ D on its heels. An option play to Hunt on the left side picked up another 11 and the Chiefs had first-and-goal from the 6-yard line. Hunt was called upon again on second down, but Simmons snuffed out a fake jet sweep to Hill to take the speedy back down in the backfield. Smith couldn’t connect with Ross Travis on third down and KC had to settle for a Harrison Butker field goal.

Siemian’s second interception of the game came on the third play of the next drive. Scrambling on third-and-five, it looked like Siemian could have run for a first down. Instead, he heaved a 50/50 ball downfield to Jordan Taylor, only to have Parker come down with it.

The Denver defense would answer again, though, forcing another turnover with Smith and the Chiefs driving into Denver territory. Shaquil Barrett got to Smith with a strip sack, which Domata Peko fell on to give the offense one last chance to redeem itself.

After a quick strike to Thomas for eight yards, Siemian missed Bennie Fowler on second down and was sacked on third down to force one final punt of the half.

Alex Smith took a knee after a 48-yard Dixon punt and the Chiefs took a two-touchdown lead into the locker room.