Parker looked in control against Minnesota, but Josh Willingham homered twice -- once off Parker early, and again off reliever Ryan Cook to put his team in front for good in the eighth -- to lead the Twins over Oakland 4-3 Tuesday night.
Parker, who gave up seven hits with two walks and four strikeouts in six innings, hasn't lost a decision since May 22, a span of 19 games. But that was of little consolation to the 24-year-old righty.
"I'm not happy that we lost, no matter what," Parker said. "Got to move on."
Parker also gave up a homer to Oswaldo Arcia, who helped Minnesota snap Oakland's three-game winning streak and prevented the A's from stretching their two-game lead over Texas in the AL West. The Rangers lost to Pittsburgh, 5-4.
Despite giving up the homers to Willingham and Arcia, Parker appeared to be on the verge of earning his 12th win. But Arcia singled off reliever Sean Doolittle to lead off the eighth. Doolittle struck out Ryan Doumit before being pulled for Cook (6-4), and Willingham followed by launching a 2-0 pitch an estimated 439 feet into the middle deck for his second multi-homer game this season.
It was only the second homer Cook had given up all year.
"I literally threw the ball right down the middle, and he did what he was supposed to do with it. ... I couldn't have put it in a better spot for him," Cook said.
Willingham hadn't homered since Aug. 13 and entered the game hitless in his last 15 at-bats. Normally accustomed to batting cleanup as Minnesota's designated hitter, Willingham batted sixth and played left field on Tuesday night.
"Obviously he feels a little bit better," Minnesota manager Ron Gardenhire said. "So that was nice to see him get that, he needed to get a smile on his face. It's been a battle for him."
Twins starter Liam Hendriks worked 5 1/3 innings and matched his career high with six strikeouts. He had a one-run lead for most of those innings thanks to Willingham's second-inning solo shot.
"He likes playing against the teams he used to play for," a grinning Hendriks said of Willingham, who played a season with Oakland.
The A's took a 2-1 lead when Alberto Callaspo sent a 1-1 pitch 384 feet into the right-field seats after Hendriks hit Yoenis Cespedes to lead off the fifth. Hendriks hit another batter, Brandon Moss, the next inning and Cespedes followed with a run-scoring single to put Oakland up 3-1.
Parker got into trouble in the sixth after Arcia led off with a monster homer to right. Three of Minnesota's next four batters reached to load the bases for Pedro Florimon. But after a meeting on the mound, A's manager Bob Melvin elected to leave Parker in the game, and he calmly induced Florimon into a double play to end the threat.
"We needed one more out, and we're in position to win the game," Melvin said. "I'm not going to go back and go over every play of the game. At the end of the day, we're one out away from getting into the ninth inning with a lead."
Callaspo's homer was his second since joining the A's. ... Oakland reinstated OF Josh Reddick (wrist) from the 15-day disabled list before the game. He wasn't in the lineup. ... INF Josh Donaldson also returned after missing one game with a sore right quadriceps. Donaldson went 1 for 4 and singled in the sixth. ... Minnesota has won seven straight at home against the A.L. West. ... After Florimon's double play, Minnesota is batting .228 this season with the bases loaded. . Cespedes is hitting .400 in nine games this month (14-for-35). . Oakland will send Sonny Gray (2-3) to the mound on Wednesday for his eighth-career start. Minnesota counters with Mike Pelfrey (5-11), who makes his first career start against the A's.