Blanton (6-6) gave up seven hits and struck out seven while going the distance for the sixth time in his career, snapping an ugly string of five straight starts with at least five runs allowed. Ty Wigginton also homered for the Phillies, who took two of three from a Minnesota team that was unbeaten in its previous four series.
Trevor Plouffe homered for the third consecutive day and fifth time in six games for the Twins. Scott Diamond (5-2) gave up four runs and five hits in six innings.
Jimmy Rollins added three hits, and Carlos Ruiz and Placido Polanco drove in the final two runs for the Phillies.
With Roy Halladay, Cliff Lee and Cole Hamels in the starting rotation, the Phillies were supposed to be immune from losing streaks and deep enough to weather an injury or two. But the starters have struggled of late to pick up the slack after Halladay went down with a shoulder injury on May 29, carrying an ERA over 6.00 into the game since losing their ace.
Blanton had been one of the biggest problems, getting tagged for 29 earned runs over his previous five starts. He gave up 11 homers in that stretch, but found some comfort at spacious Target Field. He gave up a solo homer to Plouffe in the second inning, but wasn't hurt after that.
The right-hander scattered four singles over his final seven innings, mixing his fastball and changeup effectively to keep the Twins off balance. He got a scare in the sixth when Justin Morneau just missed a two-run homer on a drive that was caught by Shane Victorino at the wall in center field, but other than that it was fairly effortless as he was able to give Jonathan Papelbon the night off after the closer picked up a four-out save on Wednesday.
Diamond had emerged as Minnesota's surprising ace since being called up from Triple-A Rochester and making his season debut on May 8. The lefty entered the game with a 1.61 ERA and riding a 13-inning scoreless streak.
That ended in the second when Wigginton hit a solo shot to left field and Big Jim introduced himself in the third inning.
Thome's three-run homer landed in the flower bed above the scoreboard in right-center, giving the Phillies a 4-1 lead and Thome 607 homers in his brilliant career. He currently sits in eighth place on baseball's career list, but Sammy Sosa (609) is in his sights.
Several fans leaned over the railing and rummaged through the flowers in hopes of getting their hands on a piece of history, but none were able to find it. A Twins spokesman said the team planned to dig it out Friday afternoon and send the ball to Thome, who spent most of the previous two seasons in Minnesota.
Joe Mauer and Alexi Casilla had two hits apiece for the Twins.
NOTES: Thome's homer was his 99th in a Phillies uniform. One more and he becomes the fourth player to hit at least 100 homers with three teams, joining Alex Rodriguez (Mariners, Rangers, Yankees) Reggie Jackson (Angels, Yankees, Athletics) and Darrell Evans (Braves, Giants, Tigers). ... The Twins placed RHP P.J. Walters on the disabled list with a shoulder injury, and manager Ron Gardenhire stressed to him that he needs to make the team aware when he isn't feeling right. Walters started the game on Wednesday, but had to be pulled in the first inning. "That's the mistake," Gardenhire said. "You've got to trust (the trainers) in that room and let them do their job." ... The Twins will open a series against the Milwaukee Brewers at Target Field on Friday night. LHP Francisco Liriano (1-7, 6.45 ERA) will face Milwaukee RHP Yovani Gallardo (5-5, 4.21). ... The Phillies leave for Toronto, where RHP Vance Worley (3-2, 3.00) will face Blue Jays RHP Drew Hutchison (5-3, 4.66) in the opener Friday night.