MINNEAPOLIS (AP) -- Erik Kratz homered twice after replacing an ailing Salvador Perez, and Jason Vargas pitched seven strong innings to lead the first-place Kansas City Royals to a 6-4 victory over the Minnesota Twins on Monday night.
Vargas (10-5) allowed one run on four this and struck out three, but had his scoreless innings streak snapped at 17 when Oswaldo Arcia hit a solo homer in the seventh. Perez had two hits and two RBIs before leaving in the seventh because of discomfort in his right knee, helping the Royals win for the 21st time in 26 games.
Kansas City extended its lead over the idle Detroit Tigers in the AL Central to two games.
Trevor May (0-2) gave up three runs on seven hits and walked four in 4 2-3 innings for the Twins.
When Perez left, Kratz came in as a pinch hitter and drove a pitch just over the wall in left field for a 4-0 lead. He added a solo shot to center in the ninth for his first multihomer game.
Trevor Plouffe hit a three-run homer off Aaron Crow in the ninth inning, but Greg Holland came on for his 38th save in 40 tries. Josh Willingham had three hits and Alex Gordon and Billy Butler each had two for the Royals, who have won eight straight series for the first time since 1991.
May made his major league debut on Aug. 9, and it was a rough one. He walked seven batters in two innings and gave up four runs. He breezed through four innings of his home debut, but walked the bases loaded in the fifth.
Perez followed with a two-run single and Butler added an RBI single to give the Royals a 3-0 lead.
That was enough for Vargas, who has dominated the Twins this season. He retired 10 in a row from the second through sixth while his offense built him a cushion.
Royals: Perez is day to day with a sore knee.
Twins: Byron Buxton, one of the top prospects in baseball, flew to Fort Myers, Florida, to begin his recovery after a nasty outfield collision at Double-A New Britain. GM Terry Ryan said Buxton had a stiff neck and some headaches, but nothing more serious. Ryan said he doubts Buxton will play again this season.
"We're all fortunate it ended up the way it ended up," Ryan said. "We've seen collisions in our day, but that one ranked right up there."
The Royals open a two-game interleague series in Colorado. RHP James Shields (11-6, 3.29 ERA) starts the opener against LHP Tyler Matzek (2-8, 5.50).
The Twins stay home for a three-game series against Cleveland. RHP Kyle Gibson (11-9, 3.96) starts the opener against RHP Trevor Bauer (4-7, 4.35).
Twins manager Ron Gardenhire didn't stick around very long. When plate umpire Chris Segal called Joe Mauer out on strikes in the first inning, the mild-mannered first baseman argued that he fouled the third strike and it hit the dirt before Perez caught it. Segal disagreed, and Gardenhire came to Mauer's defense before returning to the dugout. Moments later, Segal ejected Gardenhire after the conversation apparently continued from the dugout. It was the fifth time this season and 72nd time in his career that Gardenhire was ejected.