ANAHEIM -- It's been an admittedly tough season for Justin Speier.

The right-handed reliever was one of the Angels' top pitchers out of the bullpen last season, when he had a 2.88 ERA, which was the second lowest on the team.

But this season has been a struggle as his ERA has skyrocketed to 5.26, and it's been difficult for him to peg why he hasn't been successful as he has in years past.

"I make a mistake and this year they're getting it," Speier said. "I just haven't been getting the kind of results I like and it's been frustrating. But at the same time I know that I can finish the season strong and help the team out."

Speier made another mistake on Thursday, as he gave up a triple in 12th inning to Nick Punto, who later scored what proved to be the winning run in the Angels' 2-1 loss to the Twins at Angel Stadium.

Punto hit a triple off the glove of a leaping Torii Hunter in right-center field and scored two batters later on Denard Span's hard-hit ground ball past third baseman Chone Figgins.

"I've got to catch that," Hunter said of the ball Punto hit. "If it hits your glove, you have to catch it. I make those plays nine out of 10 times. And [Speier] has been struggling for a while, so you have to catch that and give him his confidence back."

But Speier deferred the blame, saying it was his fault that he left a 90-mph fastball up on a 2-1 count.

"I threw that ball down the middle and he hit it a long way," Speier said. "If I make a mistake like that, I take full responsibility."

The loss spoiled a great effort by Angels right-hander Lackey, who allowed just one run on five hits while striking out six. And Francisco Rodriguez, Scot Shields and Darren Oliver combined to throw three scoreless innings in relief.

But it was the Angels' bats that struggled, as they managed just five hits, only one of which came after the fourth inning. Howie Kendrick's 10th-inning single was the first by the Angels since Mark Teixeira led off the fourth with a single. Kendrick and Teixeira were the only Angels runners to reach second base after the first inning.

"We just didn't play well, especially in the batter's box," Angels manager Mike Scioscia said. "When you don't play well, you're trying to look for a break to win the game but that's not the way our team goes about our business. We like to play at a high level so that a break here or there doesn't make you lose."

Scott Baker stifled the Angels after allowing a solo home run to Teixeira in the first inning. Teixeira gave the Angels their lone run on a homer, hitting an 0-1 changeup over the center-field fence for his fifth home run with the Angels.

But Baker settled down after the homer, retiring 20 of the next 25 batters, stretching until the eighth inning. He allowed only one runner to get past first base, with that coming in the fourth inning when Teixeira singled and reached second on a walk by Vladimir Guerrero. Baker threw eight solid innings, allowing just one run and four hits, none of which coming after the fourth inning.

"He was just hitting his spots," Hunter said. "He had his fastball and slider working. If you have a guy like that hitting his spots, it's tough to hit him."

Meanwhile, Lackey cruised through the first four innings before surrendering a run in the fifth inning on an RBI single by Carlos Gomez after Punto doubled. Lackey then hit Span with a pitch before retiring Alexi Casilla to end the rally.

Lackey got in trouble again in the eighth when Gomez singled to open the inning. Lackey then made a throwing error on a bunt by Span that moved Gomez to third and Span to second with no outs.

But Lackey struck out Casilla and got Justin Morneau on a hard-hit double-play grounder to end the inning. Second baseman Kendrick got the ball to Erick Aybar, who threw to first to barely turn the double play.

"It was a great play," Lackey said. "Aybar was crushed and was able to still turn it, and Howie made a great play because he was way over in the hole."

The Angels have lost six of eight games but still have a 15-game lead over the Texas Rangers in the American League West.

"I feel like we're going through a little bit of a lull, which is OK," Speier said. "We have a lot of professionals on this team. Last year, we had our lull at the end of the season into the playoffs, so for me, if we're going to go through a lull, I'd rather it be it now and then come out of it at the end of the season strong and into the playoffs."