MINNEAPOLIS — Erik Kratz had played in only five games for Kansas City since being acquired from Toronto in a trade on July 28.

But the big guy always stayed ready and that discipline paid off Monday night to keep the Royals rolling.

Kratz homered twice after replacing an ailing Salvador Perez, and Jason Vargas pitched seven strong innings to lead the first-place Royals to a 6-4 victory over the Minnesota Twins.

Vargas (10-5) allowed one run on four hits 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 broke his bat on a pitch from Anthony Swarzak, but still managed to muscle it over the wall in left field for a 4-0 lead. Kratz added a solo shot to center in the ninth for his first multihomer game.

The drives proved even more important when Trevor Plouffe hit a three-run homer off Aaron Crow in the ninth inning.

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 bench. 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.