OAKLAND -- For most of the year, the A's offense limped along while the Oakland pitching did the heavy lifting.

It's been an about face in the second half, however, as Thursday's 8-6 win over the Twins encapsulated. The pitchers couldn't hold leads of 2-1 and 6-3, but Coco Crisp delivered his career-best 21st homer in the eighth inning to give the A's their 90th win of the season.

It was one of three homers for Oakland Thursday and it reduced the A's magic number for winning the American League West to four games. Any combination of A's wins and Rangers losses totaling four gives the A's a second consecutive title.

"When he's going good,'' batting coach Chili Davis said, "We're going good. That's the way he is.''

Part of that is that Crisp, who hit 11 homers for Oakland last year, knows his swing, and he knows the league.

"He understands his swing,'' manager Bob Melvin said of Crisp. "When he pulls the ball, he uses the shortest part of the park to hit the ball out. He has got a good understanding of where his power is.''

The A's offense is on a major roll. Oakland's 74 homers since the All-Star break is the most in the big leagues. Crisp has a dozen of those, and 11 in the last 27 games. About the time Crisp started to generate offense, the A's did as a team.

"We've been riding him all year,'' winning pitcher Sean Doolittle said. "That's what team baseball is all about. They've kind of picked us up.''

The bullpen has been something of a problem for the A's for the last two months. In August, Doolittle stumbled before finally righting himself. In September it's been Ryan Cook and Grant Balfour who've had problems. Cook was given a two-run lead Thursday but wound up getting just one out while giving up the tying runs. "The bullpen has done a great job all year,'' Crisp said. ``They took care of us when we were not hitting. They've been there the whole year.''

Oakland Athletics’ Josh Reddick (16) scores at home plate on a sacrifice fly hit by teammate Stephen Vogt (21) while playing against the Minnesota
Oakland Athletics' Josh Reddick (16) scores at home plate on a sacrifice fly hit by teammate Stephen Vogt (21) while playing against the Minnesota Twins in the fourth inning of their game at O.co Coliseum in Oakland, Calif., on Thursday, Sept. 19, 2013. (Jose Carlos Fajardo/Bay Area News Group)

Before the game Crisp was presented with the Catfish Hunter Award. The A's give it out each year to a player whose performance on the field ``best exemplifies the courageous, competitive and inspirational spirit'' demonstrated by the late Hall of Fame pitcher. The winner is determined by a vote of players, coaches and staff. "To get the award was very humbling,'' Crisp said in a somewhat raucous Oakland clubhouse. ``I'm grateful the guys feel the way they do about me.''

As a group, the A's have been on a home run tear for the six weeks, and it hasn't been just Crisp. Alberto Callaspo hit a pinch-hit solo homer in the sixth to tie the game with two out, and after Crisp and Josh Donaldson reached base with singles Jed Lowrie delivered his 13th homer, a three run-bomb that put the A's in a 6-3 lead.

Thursday's three homers give the A's 60 in their last 40 games since Aug. 9, also the best total in the big leagues over that stretch. Much as was the case last year, the A's have gone from a team that manufactured runs to a team that feels the next homer is just one swing away.

Six of the eight runs Thursday came on homers. All four runs Wednesday, ditto. "We'll take the home runs when they come,'' Melvin said. ``We know we can manufacture runs if we need to.''

Lately, that's not often.

-- Oakland now has 17 90-win seasons since moving to the East Bay from Kansas City in 1968. Over that time, only the Yankees have reached 90 wins more times.

-- The A's say there's a chance that Yoenis Cespedes could be back in the lineup Friday as the DH after the left fielder had a cortisone shot in his ailing right shoulder after Wednesday's game. Before the series opener with the Twins, Cespedes told manager Bob Melvin Thursday afternoon that he was, in the manager's words "feeling real good.

"We're hoping he can play tomorrow,'' Melvin said.

-- After essentially giving up on any chance of getting catcher John Jaso back this season after two months given away to a disabling concussion, the A's are now wondering if Jaso can help them after all. Jaso will take part in instructional league games starting on Monday.

"I have no idea what happens after that,'' Jaso said. ``I don't know if there's a chance to play some in the post-season, if there is a chance to possibly move me in some post-season scenario. I'm feeling much better, though.''

Friday's game

Minnesota (Andrew Albers 2-3) at A's (Bartolo Colon 16-6), 7:05 p.m. CSNCA