Eric Hosmer hit the go-ahead three-run homer in the fifth inning, as Kansas City downed Detroit, 5-2, in the rubber match of a three-game series.
Alex Gordon and Billy Butler each contributed a pair of hits and a run driven in for the Royals, who took the final two contests in the set and have won six of their last eight overall.
"You want to be at your best this time of year, and our guys are sure doing that," Royals manager Ned Yost said. "I like everything about our club right now. I like our bullpen, I like our starting pitching, our defense has been spectacular, we're running the bases extremely well -- we're very aggressive on the bases, too."
Bruce Chen (7-2) served up just five hits and a pair of runs with four strikeouts over seven solid innings. Greg Holland tossed a scoreless ninth for his 40th save.
Jose Iglesias hit a two-run homer for the Tigers, who have dropped five of seven but still maintain a healthy lead over Cleveland in the AL Central.
Doug Fister (12-8) was charged in the loss for eight hits and five runs across 6 1/3 frames.
The Royals went ahead in the fifth, as Gordon and Emilio Bonifacio singled with two down and Hosmer launched his 16th homer of the season to center for a 4-2 lead.
"It was right where he wants it," Fister said. "I was trying to get him to roll it over or pop it up. I left it middle of the plate too much. Trying to make him use the big part of the ballpark and that's what he did."
Jarrod Dyson began the home seventh with a triple and eventually came around on a Gordon base hit for a three-run edge.
Kelvin Herrera turned away the Tigers in order in the eighth and Holland served up a two-out double to Prince Fielder before retiring Victor Martinez on a grounder to second to end the game.
In the third, Alex Avila singled with one out and Iglesias followed with a two-run shot to left.
Bonifacio walked, moved up on a Hosmer single and scored on a Butler base hit for a 2-1 game in the home fourth.