KANSAS CITY, Mo. -- For the third time in four weeks, the offense of the Kansas City Chiefs looked out of sorts for a large chunk of the game, with quarterback Patrick Mahomes being pressured and his receivers unable to get consistent separation from coverage.

The difference on Sunday, was that the prolonged dry spell cost the Chiefs a victory.

"It caught up with us today," Mahomes said after a 40-32 loss to the Las Vegas Raiders at Arrowhead Stadium. "We've got to go back and really look at ourselves in the mirror ... and not rely on these crazy plays where I'm scrambling around and throwing these shots and just execute the offense the way that it's called and run the way it's supposed to be run. If we do that, we'll be a hard team to stop."

The Chiefs scored 24 points in the first half, matching the Raiders' output. But they lost the game during the third quarter and first half of the fourth, when the Raiders scored 16 points and the Chiefs were shut out.

The Chiefs managed a touchdown in the final four minutes to make things interesting, but it wasn't enough. The scoreless spell mirrored similar unproductive stretches for the offense against the Chargers and Patriots. As he was in those games, Mahomes was often under pressure without the opponent having to blitz and receivers had trouble getting open.

Las Vegas blitzed only three times, or on 6% of Mahomes' dropbacks (Mahomes went 3-for-3 for 85 yards on those plays). That's the second-lowest blitz rate he has faced in his career. Still, the Raiders got pressure on Mahomes 28 times in 48 dropbacks (57%) -- the second-highest pressure rate of Mahomes' career.

If the Chiefs don't protect better against three or four pass-rushers or don't get open quicker against seven or eight defenders in coverage, their offensive struggles might continue.

"We had one bad quarter, but when you're playing a team that's hot like they were, one bad quarter loses you a football game," Mahomes said.

The Chiefs lost two touchdowns to penalties. They recovered one of the drives to kick a field goal but punted on the other. Those lost 11 points would have been useful in an eight-point defeat.

They also had a 10-yard holding penalty on first down on two first half drives and wound up punting.

"Anytime you're going backwards, holding calls and things of that nature, it doesn't really give the offense a chance to succeed," tackle Mitchell Schwartz said. "Against a good team especially, you can't have negative plays ... the percentages of touchdown drives especially plummet when you give up a sack or you give up a penalty.

"It definitely has to be better. We know that and coming out that's probably going to be the biggest thing that we work on."

The Chiefs have been good at overcoming those types of setbacks but weren't on Sunday.

"In this league, when you're in first-and-20, second-and-20, it's hard to get first downs," Mahomes said. "We've been spoiled that we've kind of done it well these last few years but you don't want to be in those positions."