BALTIMORE – Ricky Nolasco's seven shutout innings Tuesday at Kansas City looked like a breakthrough. Sunday, it look more like the exception.

Nolasco's mysterious ineffectiveness returned with a thud against the Orioles, and the Twins righthander followed his best performance of the season with perhaps his worst. He gave up a season-high eight runs over five-plus innings, and the bullpen surrendered four more in the Twins' seventh loss in eight games, 12-8 to AL East-leading Baltimore.

"I wasn't able to put anybody away. I got ahead of a ton of guys, and just let them back into counts," Nolasco said after the free-agent acquisition inflated his ERA to 5.96. "They crushed the ball today, but I feel like I kind of beat myself."

Lately, he's not the only one. Since Aug. 15, the Twins have received only three quality starts in 17 games, posting a composite 6.24 ERA. Their starters have a combined 5.08 ERA on the season — last in the major leagues for the second year in a row.

Making it worse for Twins fans was the identity of Sunday's biggest culprit: yet another former Twin. J.J. Hardy victimized his old team in the manner of David Ortiz, Torii Hunter, Josh Willingham and Carlos Gomez, smacking a grand slam off reliever Anthony Swarzak that punctuated Baltimore's seven-run sixth inning.

But it was Hardy's third-inning walk that bugged Nolasco, after he started him with an 0-2 count. "I just couldn't put him away," Nolasco said, and by extending the inning, Hardy gave light-hitting infielder Ryan Flaherty the opportunity to bash a three-run homer.

The Orioles expanded their division lead to nine games with one month to go with their third victory in a row in this four-game series, while the Twins sagged to a season-worst 18 games below .500. The Twins are on pace to win only 70 games, which would give them four consecutive seasons of at least 90 losses.

Baltimore led 11-2 after six innings, but the Twins, who got home runs from Trevor Plouffe and Danny Santana, tacked on another six runs over the final three innings and forced Baltimore manager Buck Showalter to use five relief pitchers, including closer Zach Britton, who earned his 31st save on just four pitches by recording the final two outs on an Eduardo Nunez double-play grounder.

Thompson debuts

It has been three years and one embarrassing suspension since Aaron Thompson pitched in the big leagues, but he didn't doubt it would happen. "I've worked hard the past few years to put myself in this position," the lefthanded reliever said. "Now it's a situation where you really want to make the most of your opportunity, and try to stick on a team somewhere."

He took a good first start Sunday, facing four batters and recording four outs, albeit with the help of a double play. Thompson, called up to fortify the bullpen when Samuel Deduno was claimed off waivers by Houston on Saturday, struck out one.

"It looked like he was a little nervous," Twins manager Ron Gardenhire said, "but he settled down and threw a nice breaking ball."

Thompson, 27, said he is a different pitcher than the one who had a 7.04 ERA in four games with Pittsburgh in 2011, and maturity is a big reason. After signing with the Twins that winter, he was suspended for 50 games for a "drug of abuse" violation — an incident, he says now, that actually helped him.

"I kind of shot myself in the foot with some personal decisions. but to tell you the truth, I wouldn't trade that. I grew up a lot," Thompson said. The worst punishment, he said, wasn't sitting out or being in the news, "it was having to call my mom, and say, 'Mom, I messed up.' "