MINNEAPOLIS (AP) -- What has already been a long season for Oakland just keeps getting longer.

Kevin Slowey had a career-high 12 strikeouts and Brian Buscher matched his career best with five RBIs in the Minnesota Twins' 13-2 victory over the Athletics on Tuesday night.

Buscher had three hits, including a two-run homer, and the Twins pummeled Sean Gallagher (1-2) for 10 earned runs in five innings to bounce back from a lackluster effort in a 3-2 loss to Oakland on Monday.

Justin Morneau had two doubles among his three hits and every Twins hitter registered at least one hit against Gallagher and Santiago Casilla, who gave up three runs in the sixth.

The Twins remained one game behind first-place Chicago in the AL Central.

It was one of the ugliest losses in a season full of them for the A's, who fell to 6-24 since the All-Star break, trail the Angels by 19½ games in the AL West and haven't won consecutive games since July 10-11.

As bad as it was for Oakland on the mound, it only got worse when the A's stepped to the plate against Slowey, a finesse pitcher who relies more on location and smarts than heat and power.

After striking out just three hitters in his previous two starts combined, Slowey (10-8) racked up the most strikeouts by a Twin since Johan Santana fanned 17 Texas Rangers on Aug. 19, 2007.

Jack Cust struck out three times, bringing his season total to a staggering 156. It was his 45th multi-strikeout game and the 17th time this season he's struck out at least three times in a game.

Slowey allowed two runs -- one earned -- and five hits with no walks in seven innings. His lone mistake was to Kurt Suzuki, who hit the first pitch of the second inning into the seats in left to give the A's a 1-0 lead.

Buscher's two-run shot and an RBI triple by Denard Span had the Twins up 3-1 after two innings. Brendan Harris and Morneau had run-scoring doubles in a three-run third to put the Twins ahead 6-1.

With his bullpen overextended after ace Justin Duchscherer left with an injured hip in the third inning on Monday night, A's manager Bob Geren had to leave Gallagher out there longer than he would have liked.

Carlos Gomez's homer highlighted a four-run fifth that pushed the lead to 10-2, and Geren could bear to watch no longer.

The 10 runs allowed by Gallagher were the most by an Oakland starter since Colby Lewis allowed 10 to the Chicago White Sox on May 22, 2007.

Game notes
Geren did not have an update on Duchscherer before the game. He was flying home to California for an examination. ... Twins C Joe Mauer extended his hitting streak to a career-high 12 games with a single in the third. ... The Twins played without LF Delmon Young (ankle) and SS Adam Everett (hand). Both could miss the series finale on Wednesday as well. ... It was the struggling Gomez's sixth homer, but first since June 6, a span of 224 at-bats.