Eduardo Rodriguez pitched brilliantly for Boston in the opener of the day-night double-header. Another rookie, Minnesota's Trevor May, was even better in the second game.
The Twins' right-hander allowed two hits over seven innings to lift Minnesota to a 2-0 victory and a split of the doubleheader on Wednesday.
In the first game, the Red Sox left-hander allowed one run and two hits in seven innings in a 6-3 win.
"You kind of count on your veterans over the long haul," Twins manager Paul Molitor said, "but when young guys can step in and play a part in what kind of season unfolds for your club, it's a huge lift."
May (4-3) only allowed runners in the third inning. With two outs, Carlos Peguero singled and took third on a double by Dustin Pedroia, his fifth hit of the doubleheader. But Brock Holt grounded out.
May struck out nine and walked none. He has issued one walk with 26 strikeouts in 26 2-3 innings over his last four starts.
"If I'm going to get beat I'm going to make the other team beat me," he said.
Glen Perkins pitched the ninth for his major league-leading 20th save in as many chances.
Boston's Rick Porcello (4-5) rebounded from two starts in which he gave up 13 runs in 11 1-3 innings. On Wednesday night, he allowed two runs and five hits with five strikeouts and no walks in eight innings but still took the loss.
"He got better as the night went along," Red Sox manager John Farrell said. ""We just couldn't get anything going offensively."
Both Twins runs came in the second. Eddie Rosario singled and scored on Chris Herrmann's double. Herrmann took third on a single by Aaron Hicks and scored on a sacrifice bunt by Danny Santana.
In the opener, Rodriguez followed his major league debut with another outstanding performance. He became the first pitcher since at least 1900 to pitch at least seven innings, allow no more than three hits and no more than one run in each of his first two outings.
"He's a pleasure to watch," Farrell said, "a special kid."
Obtained from Baltimore for reliever Andrew Miller at last year's trade deadline, Rodriguez (2-0) made his debut seven days ago in a 5-1 win at Texas that he left after giving up three hits in 7 2-3 shutout innings.
He was surprised last year when the Orioles traded him, he said, "but look at where I am right now. Now I'm going to say thanks to them."
Farrell is thankful to have Rodriguez in Boston's struggling rotation and has no plans to send him back to Boston's Triple-A team in Rhode Island.
"If he goes to Pawtucket," Farrell said with a smile, "it's only on the way to Baltimore" where Boston starts a trip Monday.
Rodriguez allowed a solo homer by Brian Dozier in the third and an infield single by Santana in the sixth. Alexi Ogando gave up a two-run homer to Eduardo Escobar in the ninth.
The opener was a makeup for Monday night's rainout.
The Red Sox scored five runs in 4 1-3 innings against Phil Hughes (4-5). Mike Napoli added a solo homer, his ninth of the season, in the seventh against Michael Tonkin, making it 6-1.
Pedroia had four singles, Xander Bogaerts added three and David Ortiz had two doubles.
"It's not very fun when you feel like you're just constantly trying to battle out of jams," Hughes said.
After going 1-6 on a road trip, Boston got its second outstanding pitching performance against Minnesota. Clay Buchholz allowed three hits in eight innings in a 1-0 series-opening win Tuesday night.
"Everybody's throwing the ball well," Porcello said. "We need to keep doing that to provide some support for our offense."