KANSAS CITY, Mo.(AP) When the first-place Detroit Tigers rolled into last-place Kansas City this week, they had good reason to hope for a three-game sweep.

Instead, the Tigers got swept themselves - by three spot starters.

Alex Gordon and Alberto Callaspo homered in a 7-4 victory Thursday and the Royals surprised Detroit with their first three-game sweep of an American League team at home all season. They're on their first four-game winning streak since June 12-16.

''It feels absolutely tremendous, especially considering the three starters that we did it against,'' Kansas City manager Trey Hillman said. ''I'm really proud of what we were able to do this series.''

With Minnesota also losing on Thursday, the Tigers retained their 5 1/2-game lead in the AL Central as they headed back to Detroit for a seven-game homestand. But the momentum they brought to Kansas City on the heels of a six-game winning streak had definitely disappeared.

''Anybody who starts believing on how good they are is crazy, 'cause the baseball gods will bite you,'' Tigers manager Jim Leyland said.

Zach Miner (6-5) gave up three runs and five hits in relief for the Tigers, who were fresh off a three-game sweep at Tampa Bay.

Not only had the Royals dropped four in a row when the Tigers arrived, they were missing injured pitchers Gil Meche and Brian Bannister and had lost 24 of their last 33 to Detroit at home.

But beginning with Bruce Chen on Tuesday night, the Royals proceeded to win with three straight spot starters, overcoming Detroit's Rick Porcello , Justin Verlander and Jarrod Washburn .

''That's how baseball is,'' said Washburn, who went five innings and was charged with three runs on seven hits. ''Anybody can beat anybody on a given day. Kansas City is playing good baseball right now and took it to us for three days.''

Yuniesky Betancourt drove in two runs for Kansas City, which has been struggling to avoid a 100-loss season for the fifth time in eight years.

Roman Colon (2-3) got the win with 1 1-3 innings of scoreless relief while Carlos Rosa , another September call-up, pitched the ninth for his first major league save.

Gordon's leadoff homer in the sixth on Miner's fourth pitch tied it 4-all and Billy Butler 's RBI single four batters later put the Royals on top 5-4. Callaspo, who also had a sacrifice fly, hit a solo homer in the eighth.

Callaspo's home run was upheld by video review. Umpires looked at the replay to see if a fan reached over the fence to catch the ball.

Kansas City pecked away for single runs in the first, second and fourth, taking a 3-0 lead over Washburn before the Tigers scored two in the fifth on Gerald Laird 's sacrifice fly and Placido Polanco 's RBI single.

Detroit jumped on relievers Yasuhiko Yabuta and Colon to take a 4-3 lead in the sixth with an RBI single by Wilkin Ramirez and Adam Everett 's RBI double.

Lenny DiNardo , a September call-up from Triple-A Omaha whose last major league win came in April 2008, went five innings for the Royals and gave up seven hits and two runs.

''I had a few butterflies. It's been about a year since I've been able to pitch in the big leagues,'' he said.

The Royals turned three of their five double plays when DiNardo was pitching.

''I got the ground balls when I needed to and the defense behind me made some really great plays. They were great back there,'' he said.

Callaspo had a sacrifice fly in the first and Betancourt's RBI single made it 2-0 in the second. In the fourth, Betancourt doubled and scored on Willie Bloomquist 's single.

Magglio Ordonez had three hits for the Tigers.

NOTES: Royals OF David DeJesus stretched his hitting streak to 11 games. ... The video review was the second in Kansas City this year.