OAKLAND — Three times early in Sunday's game against the Raiders, Kansas City Chiefs quarterback Alex Smith targeted running back Jamaal Charles on screen passes. Three times, Charles caught the ball, turned upfield and encountered little resistance before he reached the end zone.

Overall, Charles caught all eight passes directed his way for 195 yards and four touchdowns. For good measure, he added 20 yards rushing and a fifth touchdown in the Chiefs 56-31 win over the Raiders at the Coliseum.

"I have no clue," Raiders free safety Charles Woodson said, when asked how Charles could run wild time and again. "You've seen screens get out of the gate before, but to have a team go back to it and beat you almost every time, there's no explanation for it.

"It shouldn't happen; it did happen but it shouldn't. I don't know, man, that's hard to watch a guy run up and down the field like that, basically untouched."

Basically? Cornerback Phillip Adams might have made slight contact with Charles on the first play of the game. Or, more like it, Charles might have made contact with Adams as he hurdled him on his way to a 49-yard touchdown.

Charles definitely made it into the end zone untouched on his two other touchdowns off screen passes. That included a third-and-19 play on the Chiefs' second possession of the game, with Charles weaving his way through the Raiders defense for a 39-yard touchdown.

He also scored on a 16-yard screen pass late in the second quarter. For good measure, Charles hauled in a well-thrown pass from Smith, juked Woodson near midfield and continued into the end zone for a 71-yard touchdown that sealed the outcome after the Raiders cut the lead to 35-31.

"I thought I was going to get (swarmed) on the screen plays," Charles said. "I was surprised. When I saw nobody on me, I was like, 'Whoa I have to go.' Especially the third-and-long one I was surprised."

Raiders coach Dennis Allen said the Chiefs didn't catch his players offguard. Charles simply made plays when given opportunities.

"That's what happens when you get an explosive player like Jamaal Charles in space," Allen said. "He's hoping you miss tackles and get out of position a little bit."

That's precisely what happened, Woodson and Raiders cornerback Tracy Porter said.

"When you get a guy like that in space, you expect to score touchdowns," Porter said of the Chiefs' expectations. "If you don't rally to him, he's going to have a big day like he had today. ... It happened on a few occasions and it simply can't happen."

The 195 yards receiving by Charles represents the third most by a running back since the merger in 1970. His four receiving touchdowns are more than he had in any of his first five NFL seasons or in his first 13 games combined before Sunday.

There wasn't much to suggest Charles being such a force in the passing game Sunday.

Charles caught five of the nine passes directed his way the first time the Chiefs and Raiders played this season. He netted 50 yards on those receptions, with a long of 24.

Yet, the Chiefs gleaned from the first meeting that the Raiders defense has a penchant for pinning back its ears and getting after the quarterback. In turn, that makes them vulnerable to screens, Smith said.

"They were such a big pressure team, they have such high volume on their defense," Smith said. "They got away with it the first game."

Not the second time around. The capper came when the Chiefs dialed up a wheel route to Charles late in the third quarter on a third-and-one play.

Charles flared out of the backfield, got behind linebacker Miles Burris and hauled in Smith's perfectly placed pass and turned it into a backbreaking touchdown. Just as the Chiefs expected.

"I saw that one coming in practice," Charles said. "Our coach said this probably can go (for a touchdown) if they play the right cover on me. I saw the linebacker on me. ... He said you'll have to beat one guy on this play, and I did."

Follow Steve Corkran on Twitter at twitter.com/CorkOnTheNFL.