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 anyway 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.
The Twins scored their runs with two outs in the ninth on back-to-back doubles by Chris Herrmann and Doug Bernier.
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 reevaluate in the morning and I'll be good to go," he said. "I'm feeling better now."
NOTES: 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 on Wednesday. He was placed on the paternity list, and C Dan Butera was recalled from Triple-A Rochester.