KANSAS CITY, Mo. -- Lorenzo Cain started the season slowly, but his bat is heating up big time lately.

Cain had three hits, drove in a run and scored a run as the Kansas City Royals bested the Tampa Bay Rays 6-3 Wednesday night to complete a three-game series sweep.

Left-hander Danny Duffy, who was making his fourth start since beginning the year in the bullpen, picked up his first victory, holding the Rays to three runs and seven hits over six innings.

Duffy (1-0) struck out six, including four in a row in the fourth and fifth innings, and he didn't issue a walk.

"Oh my gosh, we've been on fire offensively," Duffy said. "Lorenzo Cain has been Lorenzo Cain. There's nothing more than that I have to say. This guy has been raking in the month of May. He is who he is. He's a great baseball player.

"(Eric) Hosmer has been doing what Hosmer has been doing for his whole career. It's been fun to watch for sure."

Manager Ned Yost was pleased with Duffy's performance.

"I thought he threw great. I thought he was terrific," Yost said. "He got us through six innings. He wasn't quite as sharp as he was last time, but was still very, very consistent with his fastball, mixed in his slider well and a good changeup."

Rays starter Chris Archer (3-7) dropped to 3-1 lifetime against the Royals, allowing five runs, four earned, on eight hits and two walks. He fanned four.

"They're not as successful as they are for no reason," Archer said of the Royals. "Hopefully we can learn from the way they play and take it to Minnesota and Arizona."

The Royals went 6-0 on their homestand against the Rays and Chicago White Sox. It was their best homestand since going 7-0 in June 1988.

Wade Davis pitched the ninth to log his 16th save in 17 opportunities, although he walked one, gave up a single Brandon Guyer and threw a wild pitch.

The Royals jumped out to a 4-0 run in the first two innings off Archer.

In the first inning, Whit Merrifield doubled, extending his Royals record with hits in his first 11 career starts, and he scored on Cain's single. Merrifield has scored in nine consecutive games, while Cain has 24 RBIs in his past 20 games.

Kendrys Morales' two-out single got Cain home.

The Royals scored two runs in the second, including an unearned run on an error by third baseman Evan Longoria.

Drew Butera's ground-ball single scored Omar Infante with the first run. Butera stopped at third on Alcides Escobar's double and scored on Longoria's fielding blunder on a Cain grounder.

The Rays got a run in the third and had another cut down at the plate.

Mikie Mahtook, who was hitless in his previous 19 at-bats to drop his average to .048, led off the inning with a double and scored on Brad Miller's single. With two outs, third base coach Charlie Montoyo waved Miller home on Longoria's two-out single to left, but Miller was out by several feet at the plate. Jarrod Dyson picked up his sixth outfield assist, which is tied for second in the American League.

Curt Casali hit sixth home run of the season off Duffy with two out in the fifth, making it 4-2.

The Rays cut the lead to one run in the sixth when Steven Souza Jr. scored on a Desmond Jennings groundout.

"We came back, came back," Rays manager Kevin Cash said. "We just couldn't quite get the big hits with the guys on. I like the way the guys continued to get out there and get on base. We just needed one or two big hits."

Infante drove home Cain with a sacrifice fly in the seventh for the game's final run.

NOTES: The Royals made four roster moves Wednesday. They placed OF Brett Eibner on the 15-day disabled list with a left ankle sprain, optioned RHP Dillon Gee to Triple-A Omaha and recalled OF Reymond Fuentes and RHP Peter Moylan from the Storm Chasers. ... RHP Chris Young will replace Gee in the rotation, starting Sunday at Cleveland. ... The Rays put RHP Brad Boxberger on the disabled list with a strained left oblique. Boxberger was on the disabled list for the first 49 games, made one appearance Tuesday and went back on the DL. ... The Rays recalled IF Tim Beckham from Triple-A Durham. ... 2B Steve Pearce was held out of the Rays lineup with right elbow inflammation. ... Royals 3B Mike Moustakas will undergo season-ending right ACL surgery Thursday with Dr. James Andrews performing the surgery in Pensacola, Fla. ... Kansas City C Salvador Perez, who has not played since Saturday because of bruised quad, took batting practice.