"We needed these games against these guys," manager Ron Gardenhire said. "We're fighting through some of the same things, with all the kids and all those things. We had to win these games."
The Twins hadn't swept a series, or won three games in a row, since June 18-20 against the Chicago White Sox. And although the Astros have baseball's worst record at 36-74 and have now lost 9 of 11 it didn't dampen the Twins' joy over their modest winning streak.
Minnesota started the six-game homestand with three straight losses to the Royals, prompting Gardenhire to call a team meeting then send an additional message with an early-morning workout.
"We couldn't keep playing that way," said right-hander Mike Pelfrey, who labored through five innings Sunday and left with the game tied at 2.
"I think Gardy was right the other day when he said it seemed like Kansas City might have wanted it a little more. That's frustrating, because we were flat. But we came out and responded. Hopefully we don't have to get an early workout next time to [get us] to play a little better, but whatever it takes to win games. I think we're all here to win; it doesn't always work out as much as it should."
Arcia led off the seventh with a home run that broke a 2-2 tie. He connected against Brad Peacock (1-4), who was promoted from Triple-A to make the start and set career highs with 10 strikeouts and seven innings pitched.
The ball bounced off the top of the tall scoreboard in right-center and back into play, but second base umpire Bob Davidson quickly signaled homer.
Morneau hit a two-out, two-run homer in the first inning after Joe Mauer drew a walk off Peacock, who was recalled from Triple-A to make the start. It was Morneau's third home run in eight games; he had hit one in his previous 17.
"He misfired on Joe and I got to see some pitches," Morneau said. "I got 2-0 and felt like I had a decent swing and pulled the ball foul, and it's still a hitter's count, and was able to be aggressive. He pitched a great game; he deserved to win that game. But that was one we needed."
The homer gave Pelfrey a head start toward his first victory in nearly a month. But he labored, needing 78 pitches to work himself into and out of trouble through four innings before it caught up with him in the fifth, when he gave up two runs on three hits and a walk.
The right-hander hasn't won since pitching six scoreless innings to win at Toronto on July 6. He's 1-3 since then but has an ERA of 3.35 in five starts. Still, 4-9 with a 5.23 ERA is not what Pelfrey was looking for in his first season back from ligament replacement surgery.
"I look in, get the sign and give it everything I have," Pelfrey said. "I'm just not making pitches."
Twins OF Josh Willingham (knee) went to join Triple-A Rochester in Durham, N.C., for a rehab assignment. He is expected to play four games with the Red Wings and rejoin the Twins for a four-game series against the White Sox, likely as the designated hitter. ... Twins C Wilkin Ramirez (concussion) was sent to Double-A New Britain to continue a rehab assignment.