Floyd Bannister's two-hitter enabled the White Sox to beat the Seattle Mariners, 7-0, last night in Chicago and clinch a tie for the AL West title.

The race will end when Chicago wins one more game or Kansas City loses one. The White Sox haven't won a title of any sort since they won the pennant in 1959. The Royals stayed alive last night by beating the A's, 6-5.

"Today was a special day," said Chicago Manager Tony LaRussa. "If things had gone right, we'd be the champions. It didn't work out, so tomorrow becomes another special day. A lot of good things can happen tomorrow, like two million."

Bryan Clark (7-8), who pitched for the Alexandria Dukes in 1979, matched shutouts with Bannister until Harold Baines homered with the bases empty in the seventh inning. The White Sox settled it with six more runs--Greg Walker and Carlton Fisk each drove in two--in the eighth inning.

Bannister (15-10) is 12-1 since the All-Star break. He struck out a career-high 12 and walked two.

Baines' homer was his 17th and provided his 18th game-winning RBI.