"He continues to make progress," Tigers manager Jim Leyland said of Verlander. "That doesn't mean you're going to pitch good every time out. He's a young guy that's done a very nice job for us."
Ivan Rodriguez went 3-for-4 with an RBI for Detroit, which owns the majors' best record at 62-29. The Tigers moved 4 1/2 games ahead of the Chicago White Sox in the AL Central and improved to 11-0 against Kansas City this season.
Verlander (11-4) walked two and struck out six. He retired 11 consecutive batters from the third to the seventh innings, before Matt Stairs reached base on catcher's interference with one out in the seventh.
In his only other start against the Royals this season, Verlander struck out seven and walked one in a five-hit shutout on May 22.
"He didn't look any different than he did in May," Royals manager Buddy Bell said.
Kansas City put two runners on against Verlander in the second and seventh but he retired Esteban German to get out of both innings. German grounded into an inning-ending double play in the second and grounded out in the seventh.
"That was big. It was first and third and it would have given them a run (in the seventh)and maybe some momentum so it was a big inning for us," Verlander said. "To be able to get through that put us into the eighth inning up six. I was pretty excited about that."
Jamie Walker relieved Verlander and pitched two innings to complete the three-hitter.
Jimmy Gobble (3-3) gave up four runs and eight hits in five innings for Kansas City. He struck out six and walked two.
"They're a good-hitting team," Gobble said. "I was just trying to minimize the damage as much as possible."
Marcus Thames singled in a run in the third and Polanco's two-run double in the fourth made it 4-0. Polanco's drive into the left-center field gap scored Chris Shelton, who led off with a single, and Inge, who walked.
Detroit added two more in the sixth on Polanco's sacrifice fly and Rodriguez's RBI single.
- Detroit SS Carlos Guillen wasn't in the lineup because he's "a little banged up," according to Leyland. With the team having an off day on Monday, Leyland is giving Guillen two-of-three days off.
- Kansas City SS Tony Graffanino was 1-for-3 to stretch his hitting streak to nine games (14-for-33).
- The game featured a Negro League tribute, with Detroit wearing the jerseys of the Detroit Stars and Kansas City donning those of the Kansas City Monarchs.
- The game was played before an announced sellout crowd of 40,210.