Slowey (11-5) gave up just three walks and struck out five while Jim Thome hit a three-run home run for the Twins, who have won four straight and seven of eight. Jason Kubel also drove in a run.
"I think more than anything I was letting my defense work behind me," said Slowey. "We got some double plays out there that always help and some of the plays in the infield were just amazing. I'm not overpowering and today was a day where I didn't have great control so I have to rely on those guys."
Coupled with Chicago's loss to Detroit on Sunday, Minnesota holds a three-game lead over the White Sox for first in the AL Central. The two teams begin a three-game set in Minnesota on Tuesday.
Vin Mazzaro (6-5) was tagged for two runs (one earned) on seven hits over six-plus innings for the Athletics, who have dropped five of their last six. Coco Crisp and Kurt Suzuki each drove in a run in the loss.
"We've been playing well, but this was a tough series," said Crisp. "We felt like we could compete with them, but they got the best of us this series. They have a good ballclub all around over there. You have to be on top of your game when you play these guys and we weren't."
The Twins grabbed the lead in the third as Orlando Hudson punched a two-out single, Joe Mauer followed with a base hit and Kubel brought home Hudson with a double for a 1-0 lead.
Slowey had given up a walk in the second and third innings and in the fifth Mark Ellis reached on an error byAlexi Casilla, but he set the next three batters down and retired Oakland in order in the sixth.
In the seventh, Jack Cust led off with a walk, and after Kevin Kouzmanoff grounded out, Ellis was hit by a pitch, but Rajai Davis hit into a double play to end the inning.
With two on and two outs in the bottom of the seventh, Thome crushed a 3-0 pitch over the right-field wall to extend Minnesota's lead to 4-0.
Slowey, having reached 106 pitches, was replaced in the eighth inning by Jon Rauch, who promptly blew the no-hitter and the shutout. With one out, Cliff Pennington doubled and Crisp followed with a two-bagger to plate a run. Daric Barton then drew a walk to chase Rauch, who was replaced by Jesse Crain.
A wild pitch advanced both the runners a base and Suzuki hit into a fielder's choice to make it a 4-2 game. Crain then got Cust looking at strike three to end the inning.
Matt Capps took the mound to close it in the ninth and gave up a leadoff single to Kouzmanoff, but Ellis hit into a double play and Davis grounded out to end the game and give Capps his fourth save of the year.
Oakland returns home to face Toronto for three games beginning on Monday...Mazzaro has dropped his last three decisions...Slowey is 4-0 over his last nine starts...The Twins have taken five of the six games against Oakland this season...Minnesota stranded 12 as the team went 2- for-14 with runners in scoring position.