DETROIT (AP) -- James Shields and Danny Duffy were too much for the Detroit Tigers' offense.
Shields allowed three hits in seven scoreless innings and was part of a combined four-hit shutout in Kansas City's 3-0 win over the Detroit Tigers on Friday night to give the Royals a sweep of a day-night doubleheader.
Kansas City won the first game 2-1 as Duffy took a no-hitter into the sixth inning and pitched a combined two-hitter.
"Huge day for us. Shields came back and, basically, matched the outing that Duffy had," said Eric Hosmer, who homered in each game.
Royals pitching held the Tigers to a run and six hits combined in the two games.
"You play 18 innings against a team like that and give up one run, you're doing something special," Kansas City manager Ned Yost said.
Tigers manager Jim Leyland said he isn't worried about his AL Central-leading club.
"It's not a concern. We got what we got. It's pretty simple," he said. "Both teams got great pitching, and we didn't must enough offense."
The Royals gained two games on Detroit to move within 6½ games of the Tigers.
"We wanted to come in here and make a statement against these guys," Yost said.
Shields (8-8) won his fourth game in his past five starts. He walked four and struck out one.
"Tonight I was pounding the strike zone but just missing with some of my pitches," Shields said. " ... I've been pitching well all season. I've got a lot of quality starts. That's what I care about, not wins and losses."
The Tigers threatened against Shields in the second and third innings.
In the second, a walk to Andy Dirks and Brayan Pena's single gave Detroit runners on first and second with one out.
But Shields got both Ramon Santiago and Jose Iglesias to hit pop-ups to the shortstop to get out of the inning.
But the biggest potential rally came in the third when the right-hander walked Austin Jackson to lead off the third inning and Torii Hunter singled him to second.
But Shields retired the next three hitters, using mostly his change-up.
Miguel Cabrera was retired on weak roller to Shields between the mound and first base on which the runners moved up to second and third.
But Prince Fielder hit a short fly ball to left fielder Alex Gordon. Despite Jackson's speed, it wasn't nearly deep enough for him to score.
Shields then got Victor Martinez to line out to right to end the inning.
"It's huge, especially with their lineup and who was coming up," Shields said. "You've got Miggy, Fielder and Victor, whose one of the hottest hitters in the league ... and Miggy, the best hitter in the league."
Luke Hochevar pitched a perfect eighth and Greg Holland worked the ninth, allowing a hit, for his 34th save. He had saves in both games of the doubleheader.
Jose Alvarez (1-3), called up from Triple-A Toledo to make the start, took the loss. He gave up two runs and five hits in 5 2/3 innings, walking three and striking out five.
Alvarez's only big mistakes came in the third with two outs. He walked Jamey Carroll and Hosmer followed with his second home run of the day, that gave the Royals a 2-0 lead. Hosmer blasted Alvarez's 1-1 change-up deep into the right-field stands for his 14th homer.
"I felt good, but I made one big mistake," Alvarez said. "I'm here to win games for this team, and I didn't do that, so I'm disappointed."
Alvarez was replaced by Jeremy Bonderman with two outs in the sixth. Bonderman got the final out of that inning and the first two outs of the seventh before being replaced by Phil Coke and Al Alburquerque.
Carroll's sacrifice fly in the seventh made it 3-0. It was an unearned run off Bonderman, whose throwing error on an attempted pickoff throw sent Chris Getz from first to third. He scored on the sac fly.
Duffy (1-0) beat Justin Verlander in the opener.
Duffy was called up from Triple-A Omaha to make his second big league start of the season, and didn't allow a hit until Cabrera's hard-hit, two out single in the sixth.
"I was glad that they finally got one, honestly, because I just wanted to pitch," said Duffy, who underwent Tommy John surgery. "I wanted to protect this arm."
Kelvin Herrera replaced Duffy in the seventh and retired the side in order. Aaron Crow worked the eighth and allowed Santiago's pinch-hit home run leading off the inning. Crow got the next three batters.