With the AL West title on the line, the surging Athletics try to sweep the Rangers as both clubs wrap up the regular season Wednesday.After clinching its first postseason berth in six years during Monday's series opener, Oakland (93-68) pulled out a 3-1 victory Tuesday to move into a first-place tie with Texas (93-68)."As long as we believe inside this clubhouse and we know we can get it done, we're going to do it. I honestly believe we're going to win tomorrow," Grant Balfour said after recording his third save in as many days. "Nothing is guaranteed, but it's about as good as. I believe we can go out and get it done."Jonny Gomes hit his 18th homer for the A's, who were 13 games behind the Rangers on June 30 but now have a share of first place for the first time since March 29.Winner of five in a row, Oakland is trying to become just the fifth team to win a division or pennant after trailing by at least 13 games."This isn't Game 7 of the World Series. It's not win or go home," Gomes said. "We're going to play loose. We're going to have fun and just continue to pass the torch. Hopefully tomorrow we get our pitching, defense and homers. That's been it for us."The reigning two-time division champion Rangers, meanwhile, have dropped six of eight -- with four of those losses coming to Oakland."No one said it was going to be easy," said manager Ron Washington, whose team had held sole possession of the division lead since April 9."We started out to play 162 games and now -- tomorrow -- it's 162. And we'll see what happens. We take it no different than we have been approaching it. We just haven't put our game together yet. Tomorrow we have to put it together. If we don't put it together, we still go to the playoffs."The loser of this game enters the postseason as one of two AL wild-card teams and will have to win a one-game playoff against Baltimore or the New York Yankees in order to advance.The A's have to be feeling good about giving the ball to rookie A.J. Griffin (7-1, 2.71 ERA), having won 10 of his last 12 outings. The right-hander yielded one run over 5 2/3 innings Friday in an 8-2 victory over Seattle, improving to 3-0 with a 2.52 ERA in seven starts by the Bay."That's the fun part of the business, you get to pitch in games that matter, especially this time of year," said Griffin, who has limited opponents to a .190 average at home.Griffin was terrific in his only matchup versus Texas, giving up two hits and two walks over six scoreless innings in a 4-3 road loss June 29.The Rangers counter with Ryan Dempster (7-3, 4.64), who has been very good recently as long as he's not facing the Los Angeles Angels. He lost to them for the second time in September on Friday and allowed a combined nine runs over nine innings in those starts, giving up 13 hits and seven walks. Not counting those games, he's won six consecutive outings while posting a 2.04 ERA.Including his time with the Chicago Cubs, Dempster has a 2.78 ERA on the road this season -- sixth-best in the majors among qualified starters.In his only career appearance against Oakland, Dempster allowed two runs over 6 2/3 innings of the Cubs' 6-2 victory June 16, 2010.Texas slugger Josh Hamilton has not homered in eight straight games to remain stuck on 43, one shy of Miguel Cabrera's AL lead but needing two to possibly prevent the Detroit star from winning the Triple Crown.