Given an early two-run lead by Dustin Pedroia, Red Sox starter Rick Porcello was trying to provide a shutdown inning. Porcello walked Aaron Hicks with one out. And it led to a big inning for the Twins.
The next four batters reached and the Twins grabbed the lead and momentum on the way to a 6-4 win on Wednesday and a sweep of their three-game series.
Torii Hunter had a two-run single and Joe Mauer added an RBI single to cap the Twins' third-inning rally for a 3-2 lead. Two of the runners who scored, Hicks and Brian Dozier, had reached on the only two walks given up by Porcello.
The Twins' rally came right after Pedroia gave Boston the lead with a two-run homer in the top of the third. The shut-down inning then eluded the Red Sox.
"That's been a little bit of a nemesis so far, to date," Boston manager John Farrell said. "It's difficult to maintain momentum when it's given right back. He gets squeezed on the 3-2 pitch to Hicks, that begins that three-run inning."
Pedroia homered again with a runner on in the fifth, but that was after Porcello (4-4) allowed a two-run homer to Hicks. He later gave up a solo shot to Eddie Rosario.
"Those tack-on runs were huge," Porcello said. "Whatever happened in the third inning happened, it's my job to put up zeroes after that. To give up two home runs after that inning was not that good."
The Red Sox scored all four of their runs off Twins starter Phil Hughes (4-4), and had opportunities against the Minnesota bullpen.
Blake Swihart flew out with a runner on second off Brian Duensing to end the seventh. Michael Tonkin got David Ortiz to hit a weak grounder to the left side with two runners on to end the eighth.
"We just got to find a way to score runs," Pedroia said. "This isn't football, you can't go out there and hit somebody, you got to calm down, you got to think the game and have a good at-bat."
Minnesota has won nine of 11 and swept Boston for the first time since June 13-15, 2006.
The Red Sox have lost six of eight.
Hughes struck out three and walked none in 6 2-3 innings. Glen Perkins pitched a 1-2-3 ninth for his 18th save in as many chances.
Hicks' two-run home run to right field in the fourth gave the Twins a 5-2 lead. It was Hicks' first homer in 171-at bats since April 24, 2014.
Porcello (4-4) allowed six earned runs in seven innings for Boston. In his past two starts, Porcello has allowed 13 earned runs in 11 1-3 innings after allowing just six earned runs in his previous 25 2-3 innings over four starts.
Pedroia, who hit a two-run home run in the third for a 2-0 lead, hit another two-run shot in the fifth to get the Red Sox within 5-4. It was Pedroia's second multi-home run game of the season - the other was Opening Day - and fifth of his career.
"That's what leaders do, they step up, and try to help their team," Twins manager Paul Molitor said.
Rosario homered in the sixth to make it 6-4.
Blake Swihart nearly tied the game in the seventh, but his drive to left field with a runner on was caught at the wall by Rosario.
UPCOMING ROSTER MOVE
Before Thursday's game in Texas, Boston plans to call up left-handed pitcher Eduardo Rodriguez to make his major league debut. "We're running through a stretch of 20 consecutive games played, so we're building in a sixth starter this time through the rotation," manager John Farrell said. Rodriguez is 4-3 with a 2.98 ERA at Triple-A Pawtucket. A corresponding move is expected to be made Thursday.
Red Sox: OF Rusney Castillo missed the game after jarring his right shoulder on a diving catch in the eighth inning Tuesday. Farrell said Castillo couldn't get loose throwing and he believes the issue is "minor in nature."
Twins: On a rehab assignment at Triple-A Rochester, reliever Casey Fien has worked two scoreless innings and was scheduled to throw again Wednesday afternoon. "He's getting close," general manager Terry Ryan said.
Red Sox: Boston opens a four-game series Thursday night in Texas with Eduardo Rodriguez making his major league debut. The left-hander will try to be the first Boston starter to win in his debut since Daisuke Matsuzaka. He'll be opposed by Texas' Nick Martinez (4-0, 1.96).
Twins: Minnesota is off Thursday before welcoming Toronto for three games over the weekend. Trevor May (3-3, 4.95) is scheduled to pitch against Toronto's Mark Buehrle (5-4, 5.13) in the series opener.