Ventura's fastball hit 98-99 mph, and he pinpointed his changeup and curve. Ventura gave up one run on six hits, walked just one and struck out six.
Ventura has now given up just three runs over 19 innings in his last three starts -- his best three-start stretch of the season.
"Looks to me like he's starting to get his swagger back," Royals manager Ned Yost said.
"I agree with what Ned said," Ventura said through interpreter Jeremy Guthrie. "I'm able to pitch inside with confidence. That's big for me."
Against the Red Sox, Ventura sailed through the first five innings without allowing a run.