Bumgarner took the loss in San Francisco's first trip to Kauffman Stadium since 2008. However, he hardly deviated from the top-quality form he's displayed on the road this season. The left-hander made a mistake in the first to Billy Butler, elevating a fastball that the first baseman pounced on for a two-run homer. Other than that, he showed why he entered Friday third in the Majors in road ERA (1.58).
"I thought he did a great job," Giants manager Bruce Bochy said. "After the first inning, he pitched great. ... He gave us all he had out there. He gave us a chance to win."
It'd be hard to place blame on Bumgarner for Kansas City's two-run sixth that keyed its victory.
The inning began with an Omar Infante single, the only well-hit ball in the frame, that ended Bumgarner's stretch of not allowing a hit at 11 batters -- a streak that started in the middle of the second.
Errant throws from first baseman Michael Morse and second baseman Matt Duffy proved costly. Morse made a diving stop on a Salvador Perez grounder headed for right field, but his throw to second pulled Duffy off the bag. The issue metastasized when Duffy's return throw skied over Morse, allowing Infante to move to third base.
"Morse had more time than he thought. You'd like to just get an out there, and Duffy, he knew he came off the bag, so he wanted to try and get an out -- we compounded the damage," Bochy said.
The well-placed hits came in the form of a Butler dribbler that split the gap between first and second to score Infante, then a lazy fly ball from Alex Gordon that fell barely out of the reach of an outstretched Juan Perez to score Salvador Perez and put Kansas City up 4-2.
Bumgarner scattered seven hits and walked zero in eight innings, his third complete game of the season and fifth of his career. All four runs were charged to him -- only the third time this season he allowed more than two runs in 14 road starts -- but just three were earned.
The left-hander persuaded Bochy to let him throw the eighth despite starting the inning at 105 pitches.
"In the eighth, he says, 'I'm telling you, I would be honest with you, I feel great,'" Bochy said. "He hadn't thrown 100 pitches the last couple starts; his load's been somewhat light. It's good to get stretched out occasionally."
Kansas City jumped on Bumgarner early. Butler hacked a high fastball into the Royals' bullpen in left field for a 2-0 lead.
"If you're going to get a guy like Bumgarner, you better do it early and we did, thanks to Billy's two-run homer in the first inning," Royals manager Ned Yost said.
The Giants countered with two in the third, although it could have been more if not for Nori Aoki's arm.
Joaquin Arias (double) and Duffy (single) each collected RBI hits, but Aoki limited the damage with two outfield assists in the frame. The first came on a Pablo Sandoval single, as Aoki gunned down Hunter Pence attempting to move from first to third on the hit. The original call was safe, but replay officials in New York overturned the ruling as Pence slid off the base while third baseman Mike Moustakas administered the tag.
Aoki recorded the final out on Duffy's RBI single. The right fielder gunned down a potential second run, Arias, at the plate, keeping the score tied at 2.
The Giants battered Royals starter Jason Vargas, but were unable to dispose of him. They had nine hits with no outs in the fourth inning, but only two runs to show for it. San Francisco did manage to force the Royals to use their bullpen early. After five innings, Vargas, 101 pitches deep, was done.
Unfortunately for San Francisco, the Kansas City bullpen rarely falters, and Friday was no exception. Jason Frasor, Kelvin Herrera, Wade Davis and Greg Holland took care of the Giants in the final four innings and handed the team its third loss in four games.
Arias finished with a pair of doubles. Before Friday, he had two doubles in his first 141 plate appearances this season.
Jackson Alexander is an associate reporter for MLB.com.