The Seattle right-hander allowed four hits in six shutout innings, and the Mariners scored six runs in the second en route to an 8-2 rout Thursday night.
The Mariners also matched their season high with three errors along with two more fumbles that were ruled hits. But Iwakuma picked up the defense each time and worked out of jams.
"Stuff like that happens in a game in a long season," the Japanese-born Iwakuma said through an interpreter. "You have to see how much you can cover up as a pitcher. That's what I have in mind."
Iwakuma (10-4), who won his third straight decision, struck out nine and walked one. Since moving into the starting rotation on July 2, 2012, Iwakuma has gone 18-8 with a 2.78 ERA in 38 starts.
"I was not real pleased with our infield play," said Mariners acting manager Robby Thompson, a former infielder. "But (Iwakuma) battled, and he got himself out of it. The infield and outfield pick up the pitchers at times -- well, he picked up the infield tonight.
"He threw more pitches than what he should have but he battled and got us out of a couple jams that we put him into."
Against the Twins, Iwakuma is 4-0 and hasn't allowed an earned run in 26 2/3 consecutive innings over his four starts -- Minnesota's third-longest streak. He has held the Twins to a .168 batting average with eight walks and 24 strikeouts.
"I don't know if I'm good against them in general, but I was able to pitch down in the zone, get ahead on the first pitch and just be aggressive with the fastball," Iwakuma said.
Felix Hernandez, who starts Friday, has the fourth-longest streak at 24 straight scoreless innings.
The Mariners matched a season high with six doubles.
Seattle, which has won nine of 10, has beaten the Twins six straight times at Safeco Field, dating to May 5 of last season.
Franklin made one of the errors at second base.
"It's definitely in the back of your mind. You do take it personally," Franklin said. "(Iwakuma) did a great job, a hell of a job the whole entire game. If the defense made a little more plays, we could have gotten him out of the innings earlier."
One of the critical innings was the third, in which the Twins loaded the bases with one out on two singles and an error by Kyle Seager at third. But Iwakuma struck out Trevor Plouffe and got Clete Thomas to bounce out to second.
Twins starter Kevin Correia (7-7), chased after just 1 2/3 innings, allowed six runs and seven hits. It was his shortest outing since June 6, 2010, when he also went 1 2/3 with San Diego against Philadelphia.
"It was obviously my worst start of the year," Correia said. "I felt all right. The first half of the second inning, I was making good pitches, and then I made a couple bad pitches, and they just kept hammering them."
Six of the first seven Mariners reached with a hit to start the second, and all six scored. Seager opened with a double off the right-center wall. Justin Smoak then singled to right.
With one out, Mike Zunino singled to left to score Seager, Ackley sent Smoak home with a single to right, Brad Miller's double drove in Zunino and Franklin hit his eighth homer of the season on an 0-2 pitch.
"The curveball kind of got me in trouble," Correia said. "I threw five or six of them. Half were really, really good, and the other half were really, really bad.
"They just kind of jumped on me, and I couldn't get them off."
Franklin's approach was simple when he was down in the count.
"I was just looking to make contact," he said. "The infield was in. I was just looking to put the ball in play and get a run home any way I could."
The six runs were the most the Twins have allowed in one inning this season. The Mariners' seven hits were their season high in a frame.
Henry Blanco and Ackley had back-to-back two-out RBI doubles in the fifth for Seattle.
Zunino, the Mariners catcher, took a foul tip off his left hand and was removed in the fifth inning for precautionary reasons. X-rays were negative.
"They'll re-evaluate in the morning, and I'll be good to go," he said. "I'm feeling better now."
Thompson, who has managed the past four games in place of Eric Wedge (mild stroke), will fill in for at least nine more games before Wedge is expected to return. ... DH/OF Mike Morse (quad), on rehab at Triple-A Tacoma, could return to the Mariners this weekend. ... Twins C Joe Mauer remained in Minneapolis after his wife gave birth to twin girls Wednesday. He was placed on the paternity list, and C Drew Butera was recalled from Triple-A Rochester. ... Miguel Sano, a top Twins prospect playing third base for Double-A New Britain, has been benched the past two days, according to the St. Paul Pioneer Press. Manager Jeff Smith held him out of the lineup for an undisclosed violation of team rules, with no time table for his return, the newspaper reported.