OAKLAND, Calif. -- The Kansas City Royals appeared headed for their fourth consecutive victory Tuesday night when Drew Butera and Eric Hosmer hit two-run homers and Mike Moustakas added a solo shot to take an four-run lead with a five-run rally in the top of the eighth inning.

The Oakland Athletics did them one run better in the bottom of the eighth.

The A's scored six times and held on for a wild 10-8 victory at the Oakland Coliseum.

Matt Joyce hit a solo home run in the first inning and a three-run double during the eighth that put the A's ahead 9-8.

"That was awesome," Joyce said. "I'm so proud of these guys. It's obviously tough to give up the runs and give up the lead there late in the game. It's obviously frustrating for everybody over here, but to be able to come back and battle and have good at-bats and start a rally and just come away with the win, it speaks a lot to these guys' ability to keep playing the game, not give up."

The Royals (60-59) fell six games behind the first-place Cleveland Indians in the American League Central. They are a half-game behind the Los Angeles Angels for the second Al wild card.

Khris Davis hit his 33rd home run for the A's, a two-run shot in the third inning, and Matt Olson had a solo blast in the second.

Alex Gordon led off with a walk in the eighth for Kansas City, and Butera hit a tiebreaking blast off reliever Santiago Casilla down the left field line.

Lorenzo Cain singled with one out off Casilla, and Hosmer greeted Blake Treinen with a two-run blast, his 20th of the season, to make it 7-4. Then with two outs, Moustakas sent Treinen's 2-0 pitch into the right field seats for his 35th home run of the season.

The A's sent 10 batters to the plate in the bottom of the eighth to regain the lead. Jed Lowrie led off with a double to right off reliever Joakim Soria, moved to third on Davis' single and scored on Ryon Healy's single. Olson followed with an RBI single.

"He was getting ahead of all the hitters, but he just didn't have his changeup tonight," Royals manager Ned Yost said of Soria. "That's a pretty big out pitch for him."

Soria struck out Matt Chapman, and left-hander Mike Minor (5-5) fanned pinch hitter Chad Pinder for the second out. Minor threw a wild pitch, moving runners to second and third, then fell behind 2-0 in the count to pinch hitter Rajai Davis, who was intentionally walked.

Joyce launched Minor's second pitch off the left field fence, clearing the bases, and Marcus Semien hit an RBI single, making it 10-8.

"I looked back on it and I thought it was a good pitch," Minor said. "The only thing I could say is it was up. I thought it was where I wanted it. It was on the outer fourth of the plate, but it was up and he put a good swing on it."

A's manager Bob Melvin couldn't say enough about his young team's comeback.

"That's really what the culture we want to set with these guys is," Melvin said. "We're going to come back, no matter what. We're going to fight. If we go down, we're going to go down bleeding."

Treinen (1-0) pitched a scoreless ninth for his first win as a member of the Athletics.

A's right-hander Chris Smith allowed three runs -- all in the first inning -- on three hits over 5 1/3 innings for a no-decision. He struck out three, walked one and left the game with a 4-3 lead. Smith trailed 3-0 after facing four batters, but after that, he retired 15 of the final 16 Royals he faced.

"Four batters?" Smith said. "It seemed like it was forever. During that first inning, I might have blacked out."

Until the A's bullpen imploded in the eighth, Smith, 36, was in line for his first major league victory as a starter and first win since June 4, 2008, with Boston against Arizona.

Royals right-hander Jason Hammel allowed four runs on eight hits, including a season-high three home runs, over six innings for a no-decision. He struck out six, walked one and pitched at least five innings for the 14th straight start.

The Royals jumped to a 3-0 lead in the top of the first inning. Whit Merrifield led off with a walk and moved to second when Smith hit Cain with a pitch. Hosmer lined a two-run double down the right field line, then scored on Melky Cabrera's single to left-center.

NOTES: Royals RHP Jake Junis will remain in the rotation but will have his turn skipped on Sunday in the finale of a three-game series against Cleveland at Kauffman Stadium, manager Ned Yost said Tuesday. The Royals have an off day Thursday, and RHP Jason Hammel will start Sunday's game on his regular four days' rest. ... RHP Chris Hatcher was acquired by Oakland from the Dodgers in exchange for $500,000 in international slot money. Hatcher is 8-14 with a 4.72 ERA in 193 career major league relief appearances. He has missed much of this season with thoracic inflammation but was reinstated from the disabled list Sunday. ... Royals C Salvador Perez (right intercostal strain) threw to second base but did not swing the bat as he continued his rehabilitation program. He took pain-free swings off the batting tee at 30-40 percent effort on Monday. "He's throwing 100 percent," Yost said.