Ian Kennedy allowed five runs on six hits in his four innings. He walked a pair and struck out six.
Giants reliever Sergio Romo struck out the side in the ninth.
Royals: Kennedy said the biggest takeaway of the day was getting his pitch count up.
"I fell behind a lot of hitters," he said. "I was hoping to go deeper into the game, get up and down a couple more times, but I threw so many pitches early on. Even the innings I wasn't giving up runs, I was throwing a lot of pitches."
Kennedy said his fastball command was not that far off and his changeup was pretty good.
"I was barely missing and I was missing down," Kennedy said. "With Belt, I didn't get it quite as high as I wanted. I tried elevating that pitch, but it didn't happen. It's about getting ready for the season rather than focus on results."
With George Kottaras in the original lineup as designated hitter, Kennedy was surprised when Cueto came to bat in the third.
"I heard his name and turned around and saw him," he said. "I was prepared to face Kottaras."
Giants: Cueto said he's ready to start the regular season after throwing over 90 pitches, using everything in his repertoire.
"Everything was working and I felt comfortable," Cueto said. "My objective was to get my work done and try to throw to the inside when I want and to the outside when I want."
Cueto led off the third inning with a single to right field and had to hustle to beat a throw by Paulo Orlando. They exchanged a few light-hearted words afterward.
"I had to run hard or get thrown out," he said. "I don't like hitting that much, but I do like moving the runner up."
Cueto enjoyed going up against his old teammates, too.
"It's always great to face old friends," Cueto said. "But that's baseball; one year you're on a team and the next year you're with another team."
Royals: RHP Edinson Volquez (arm fatigue) will have had two weeks between starts when he makes his next appearance Monday. Volquez has thrown in minor-league games. ... LHP Tim Collins (left elbow) said he would undergo a second Tommy John surgery after an MRI revealed that the first surgery failed to take hold.
Giants: C Andrew Susac (tendinitis in right hand) has not appeared in a spring game for over a week, although he has been playing in minor league games.
Royals: RHP Chien-Ming Wang will make his seventh appearance, second start, on Saturday in Surprise against the Oakland A's and RHP Chris Bassett.