The Cleveland Indians won their eighth straight game Thursday, a 6-1 decision at home to sweep a series from the Chicago White Sox. The Sox, now 40-66, are 26 games under .500 for the first time since 1980. Cleveland is now two games behind the idle Detroit Tigers. Cleveland hosts Detroit in a series which begins Monday. The Tigers, off Thursday, host the White Sox for a three game weekend series beginning Friday night. The Kansas City Royals have won nine straight games and are now 6 1/2 games out of first place in the Central Division.