With the Royals leading, 2-0, Ventura had just struck out Miguel Cabrera with the bases loaded for the second out of the inning. Facing Victor Martinez, Ventura then threw an 0-1 curveball that landed in the dirt.
Home-plate umpire D.J. Reyburn came out from behind the plate and signaled balk, which plated a run.
Ventura agreed, saying through interpreter Pedro Grifol, "To start off, I didn't balk. I know I came to a complete stop, and I felt that wasn't a good call at that particular time."
Royals manager Ned Yost and his staff also were puzzled by the call, but Yost said if he had argued, it would have been an automatic ejection. Perez got an explanation from Reyburn the following inning.
"They said that it was a non-stop [balk], which was not even close [to being true]," Yost said. "Nothing about that even resembled a balk. He came set for a full second-plus and did a nice slide step. Something threw [Reyburn] off there."
The call changed Yost's strategy late in the game. As pitching coach Dave Eiland pointed out, if the Royals had a 2-1 lead instead of being tied at 2, they would have gone to closer Wade Davis in the ninth. The outcome could have been far different.
The call and subsequent unsettling loss also overshadowed another strong performance from Ventura, who gave up two tainted runs -- the other scored after a two-out triple that was slightly misplayed by right fielder Paulo Orlando and then a wild pitch that Perez couldn't corral.
"I wanted a breaking ball in the dirt," Ventura said of the wild pitch, "and I throw it with conviction, because I know who's behind the plate and that he's going to block those baseballs. And if I get an opportunity to do that again, I'll do it again."
The last four runs scored off Ventura over his last two starts have come without any RBIs. He gave up his last two runs to Seattle the previous start on a single wild pitch.
"Those are things that are part of the game and some of those things are out of my control," Ventura said. "I only control the baseball, and what I can do with the baseball."
Ventura went seven innings, walked one and struck out six.
"A great outing," Yost said. "I mean, we should have been in the ninth inning up 2-1 in that situation. But Ventura just pitched great."
Jeffrey Flanagan has covered the Royals since 1991, and for MLB.com since 2015. Follow him on Twitter @FlannyMLB. This story was not subject to the approval of Major League Baseball or its clubs.