Lopez got Cabrera on a pop to shortstop and Hosmer lined to left. The White Sox then got six in the sixth to set Lopez up for his first White Sox win.
"He did a really nice job of settling down," Renteria said. "He was able to minimize the damage. Very nice, very composed."
By bending but not breaking, Lopez not only survived the fifth, but he came back to work a scoreless sixth before calling it a night after 95 pitches.
Getting his first win in a White Sox uniform was special for Lopez.
"It's something that's very important to me," Lopez said through a translator. "I feel very proud. Once I was traded, I knew I had to perform at my best, and I was able to do it today."
Lopez said maintaining his focus was the key in getting through the fifth inning. Four of five Royals batters had hits, including a homer and a triple. But Lopez didn't fall apart.
"Reynaldo is a kid who's learning," first baseman Jose Abreu said. "We're really happy to have him here. We know he's going to be great here."
Robert Falkoff is a contributor to MLB.com based in Kansas City. This story was not subject to the approval of Major League Baseball or its clubs.