KANSAS CITY, Mo. (AP) -- Neither the Detroit Tigers nor the Kansas City Royals saw this sweep coming.

Jose Guillen homered and drove in three runs, Gil Meche pitched seven solid innings and the Royals beat Detroit 8-4 Thursday to complete another three-game sweep of the Tigers.

Kansas City won its season-best fourth straight and improved to 6-0 this season against the skidding Tigers, who have lost four in a row and 10 of 12 while falling into last place in the AL Central.

"That's a question I ask, 'How we can sweep this team twice with the type of offense that they have?"' Guillen said. "That's baseball. You see some stuff you're never going to believe, but we did it."

The Royals began the year with three wins at Detroit, which opened 0-7 despite a $139 million payroll. Now, the Tigers (16-25) are struggling again.

"I think the confidence level has a lot to do with it," Royals manager Trey Hillman said about the latest sweep. "I think it has a lot to do with the fact that we went into their place to open the season and nobody was expecting us to do much of anything, except maybe score one win out of maybe the three wins. We swept that series. I don't deny I think there is some confidence that rubs off that to this series."

The Tigers have scored only 11 runs in the six losses to Kansas City.

"We're not stringing good at-bats together," manager Jim Leyland said. "Today's game, we had some good at-bats and we threw some at-bats away. I'm very surprised and disappointed in the results so far, but I'm not disappointed in the effort."

Billy Butler's two-run double keyed a three-run first against Tigers left-hander Kenny Rogers (3-4). Miguel Olivo doubled home Butler with the final run of the inning.

The Royals added two more in the second on an RBI single by Joey Gathright and Guillen's bases-loaded walk after falling behind in the count 0-2.

Guillen homered leading off the fourth against Rogers to extend his hitting streak to a season-high seven games. Olivo later doubled and scored on Mark Teahen's single.