"We didn't pitch good, we certainly didn't play very good defense and we didn't hit," manager Kirk Gibson said. "It's a game that we'd like to quickly forget. They pounded us."
Already down 3-1 in the fifth, things went from bad to worse for starter Wade Miley.
Miley had already surrendered a three-run homer to Salvador Perez in the third inning, putting his team in a hole. Lightning struck again for the Royals in the fifth, with Billy Butler starting the Royals' best offensive inning of the season with a three-run home run of his own.
"Everything I threw was kind of toward the middle of the plate," Miley said. "It really wasn't my night at all."
Things just got worse for Miley as the inning progressed.
With runners on the corners, Miley threw a wild pitch that bounced in front of catcher Miguel Montero. Montero whipped the ball to first baseman Jordan Pacheco to try to get Lorenzo Cain. Cain got caught in a rundown, and second baseman Aaron Hill missed the tag, allowing the runner at third, Alex Gordon, to score.
"I didn't know Gordon was going to take off like that," Pacheco said. "Soon as I looked over there, he was already halfway down the line. I tried to get an out, but then I screwed it up."
Now down, 7-1, Miley loaded the bases after striking out pitcher Danny Duffy, who reached base on a dropped third strike.
Gibson elected to take Miley, who had already labored through 100 pitches, out of the game and brought in long reliever Bo Schultz.
The Royals greeted Schultz rudely.
The first batter he faced, Nori Aoki, roped a line drive over the right-field wall for a grand slam -- his first home run of the season.
"I knew it was coming somewhere down the road," Royals manager Ned Yost said. "I was glad to see it today.
"Any time you score 10 runs off three swings of the bat, I'll take it"
Duffy probably wasn't used to having so many runs supporting him. Despite a 2.42 ERA entering Tuesday's game, he had a 5-10 record. The Royals' offense previously averaged only 2.79 runs behind Duffy -- a number sure to rise after this latest win.
"He hasn't gotten too many runs," Perez said. "We needed to get some for him."
With the Royals now holding a convincing 11-1 lead, both teams settled in for the uneventful final innings.
The D-backs eventually scored once more in the eighth inning, but the Royals restored the 10-run lead in the top of the ninth with a sacrifice fly from Cain.
"It's going to happen," said Miley, whose 10 earned runs allowed were a career-worst. "It's not the first time it's happened, and it won't be the last. So the best thing is you've just got to accept it, not drag it with you … and just kind of flush it and move on."
Adam Lichtenstein is an associate reporter for MLB.com.