KANSAS CITY, Mo. — Christian Colon hit his first career home run, and top prospect Hunter Dozier doubled for his first major league hit.

They both came way too late for the Kansas City Royals to avoid an embarrassing sweep.

Stephen Vogt homered and drove in five runs, Ryon Healy hit a mammoth three-run homer and the Oakland Athletics routed the defending World Series champions 14-5 on Thursday night.

Oakland put a huge dent in the Royals’ diminishing playoff chances, sweeping a four-game road series at Kansas City for the first time. The A’s outscored the Royals 43-12, the largest run differential for Oakland over a four-game series in franchise history.

Kansas City has lost eight of its past nine home games.

“It’s been tough,” Colon said. “We’re not used to this, so it’s hard.”

Royals starter Edinson Volquez (10-11) faced 22 batters and nine scored in 3 1/3 innings. He allowed nine runs on seven hits and four walks.

In his past four starts, Volquez has given up 20 earned runs on 32 hits and nine walks in 18 1/3 innings for a 9.82 ERA.

“I was inconsistent,” Volquez said. “I’ve been getting hit with all my pitches. I think my changeup always gets me out of trouble, but I’m still getting hit with that pitch, so that’s a bad sign for me.”

Chris Young, the third Royals pitcher, yielded the home run to Vogt and has served up 28 in 85 innings.

Colon’s three-run shot in a five-run ninth came in his 293rd major league at-bat.

“It felt good off the bat,” he said. “I wish it was under different circumstances, but it is what it is.

“A big monkey off my back, for sure. Hopefully there’s many more.”

Dillon Overton gave up all the Kansas City runs in the ninth and has allowed 12 homers in 22 1/3 innings this season.

“I faced Overton a couple of times when we played (Triple-A) Nashville, so I knew he was a fastball/changeup guy,” Dozier said. “He has a good changeup, so I was just looking to hit a good fastball early and he gave me one.”

Those were the only Royals bright spots in the finale of a dismal series.

Vogt had a two-run double in a five-run third, walked with the bases loaded in the fourth and hit a two-run homer in the sixth. The five RBIs matched a career high.

Healy, who had three hits, homered in the third with Khris Davis and Yonder Alonso on base. The ball traveled an estimated 480 feet, landing above the left-field fountains.

Has he ever hit a ball farther?

“I really don’t think so,” Healy said. “It was a changeup. I saw it well. I kept my hands back and tried to drive the ball to the outfield to score those runs.”

Marcus Semien, who knocked in four runs and hit a three-run shot in the eighth for his 25th homer, could not believe the distance on Healy’s drive.

“I’ve never seen a ball hit up there,” Semien said.

Healy went 9 for 17 (.529) with two doubles, two home runs and seven RBIs in the series.

Joey Wendle had his first career four-hit game and scored three runs as the A’s banged out 16 hits.

Rookie right-hander Daniel Mengden (2-7), who was 0-4 with a 9.39 ERA in his previous seven starts, was the beneficiary of the offensive outburst. He held the Royals to three hits over seven scoreless innings, striking out six without a walk.

VARGAS TO START

Royals lefty Jason Vargas, who needed reconstructive elbow surgery and hasn’t pitched since July 21, 2015, will start Saturday against the White Sox. Vargas will be on a 45-pitch limit over three innings. Kansas City manager Ned Yost said the goal is for Vargas to pitch 10-15 innings before the season ends. Vargas was 5-2 with a 3.98 ERA in nine starts before the injury last year.

TRAINER’S ROOM

Royals OF Lorenzo Cain, who has appeared in only one September game because of a sore left wrist, probably won’t return this season. “He’s not making great progress,” Yost said. “He’s getting a little bit better, but we’re starting to run out of time.”

UP NEXT

Royals RHP Ian Kennedy, who is 5-0 with a 2.16 ERA since the start of August, will pitch Friday against the White Sox.