MINNEAPOLIS -- Kansas City Royals catcher Erik Kratz's first two-homer game in the big leagues was certainly unexpected. It ended up being crucial.

Kratz, who didn't enter the game until the seventh inning, connected on solo homers in the seventh and ninth innings Monday, helping the Royals to a 6-4 win over the Minnesota Twins at Target Field.

The victory was the Royals' third in the four-game series here and moved them to two full games ahead of idle Detroit atop the American League Central standings.

Everyday backstop Salvador Perez started the game and played through the sixth inning. But manager Ned Yost removed him from the game with him due up third in the top of the seventh inning. Kratz snapped his bat on the first pitch he saw, but hit it hard enough to clear the wall in left for his third career pinch-hit home run.

"When it goes well, it's a simple game," Kratz said with a chuckle. "When it doesn't go well, it's a maddening game."

In the ninth, Kratz did it again, taking Twins right-hander Ryan Pressly over the wall for his first multi-homer game since Triple-A. For Kratz, a former Pirate and Phillie who was acquired in a trade from Toronto on July 28, the home runs were his first and second as a Royal.

"I have some experience pinch hitting, coming from the National League, with the way the roster is made up with the Phillies, I've got quite a few hits as a pinch hitter," Kratz said. "My first career home run was actually as a pinch hitter."

Both homers seemed inconspicuous at the time they were hit. Starter Jason Vargas was on cruise control and the Twins offense had been sputtering all night. Kratz's homer in the ninth made it 6-1, but Trevor Plouffe's three-run blast in the bottom half of the inning turned a run-away into a close game.

"They're always big for us," Yost said. "Even though you have a five-run lead, the possibility of it getting to a two- or three-run lead exists."

Vargas was nearly flawless through seven, allowing only a solo homer to Oswaldo Arcia in his final inning of work. Before that, it was three harmless singles. In between, Vargas retired 10 in a row through the middle innings, allowing only the four hits and a walk en route to his 10th win of the year.

Closer Greg Holland entered after the Plouffe homer in the ninth and got the final two outs in order for his 38th save.

After a disastrous first start in the majors Aug. 9 against Oakland, Twins right-hander Trevor May got a second chance -- this time at home. And through four innings, May looked in control, allowing only a pair of singles and a two-out double.

But as they did in his first outing, the walks finally caught up to May in the fifth. After getting third baseman Mike Moustakas to line out to start the inning, May walked three of the next four hitters he faced.

"I have no lack of confidence. I see a definite upward trend in how things are going," May said. "It's all stuff that's happened to me in my career where I've gone through rough patches and there's always adjustments that need to be made."

Three straight singles followed, scoring three runs and knocking May from the game.

"When things snowball, they happen kind of quickly," said Twins bench coach Terry Steinbach. "He got to that fifth inning and the next thing you know, a couple walks, a couple hits, and all of a sudden you're in trouble and before you blink there's three runs on the board."

May lasted twice as long as his debut, but still only made it through 4 2/3 innings, allowing the three runs on seven hits and four walks.

NOTES: Twins manager Ron Gardenhire was ejected for arguing balls and strikes in the bottom of the first inning. It was the fifth time this season and 72nd time of his career he has been ejected. ... Twins RHP Trevor May made his Target Field debut Monday. He made his first major league start Aug. 9 in Oakland, lasting only two innings, and entered in relief on Aug. 12 against Houston. ... Twins prospect OF Byron Buxton is suffering from headaches after a collision in a game at Double-A last week. Twins GM Terry Ryan said he doesn't expect Buxton to play another minor league game this season, but should be ready to play in the Arizona Fall League in October. ... Royals 1B Eric Hosmer said he could return to Kansas City on Thursday for X-rays on his fractured right hand.