Chicago (72-53) maintained a one-game lead in the AL Central over the Minnesota Twins with a 5-0 win over the Mariners (46-79) on Tuesday. Nick Swisher and Jim Thome each homered and rookie Clayton Richard allowed five hits over six innings for his first major league victory.

Seattle, which has the AL's worst record, has lost five straight and nine of 10.

Chicago's two home runs on Tuesday gave it a major league-leading 184 for the season and 10 in the last three games. Thome's homer was the 533rd of his career, moving him within two of passing Jimmie Foxx for 14th place on the all-time list.

The White Sox matched their win total from last year, when they finished 72-90 for their first losing season since 1999.

Chicago has won four straight and seven of eight. During that stretch, it's faced the three teams with the worst records in the AL - Seattle, Oakland and Kansas City.

In home series against the Mariners and Royals, the White Sox have outscored them 40-7, shutting the two teams out a combined three times.

"All cylinders are clicking right now," Swisher said. "We're getting it from batters one through nine. We're getting it on the hill. ... It's just a lot of fun right now."

Chicago looks to complete the series sweep when it sends Gavin Floyd (12-6, 3.75 ERA) to the mound.

Floyd hasn't lost since July 19 against Kansas City, going 2-0 with a 4.71 ERA in five starts. On Friday against Oakland, he allowed two runs - one earned - and six hits over 5 2-3 innings of Chicago's 6-4 loss.

Floyd is 0-2 with a 10.13 ERA in two starts and two relief appearances against the Mariners in his career. On May 11, he allowed five runs and nine hits in 3 2-3 innings of a 6-3 loss at Seattle.

Floyd is 8-2 with a 3.27 ERA at home this season and the White Sox are 11-2 when he takes the mound at U.S. Cellular Field.

R.A. Dickey (3-7, 4.92) counters for Seattle. The knuckleballer rejoins the rotation after making two relief appearances over the weekend at Minnesota. The right-hander is making his 13th start this season and is taking the rotation spot of the injured Carlos Silva.

Dickey pitched 3 1-3 innings against the Twins, allowing two runs and four hits. He tied a major league record on Sunday after throwing four wild pitches in the fifth inning.

As a starter, Dickey is 2-7 with a 6.03 ERA. He is 0-1 with a 5.56 ERA in three relief appearances against the White Sox and hasn't faced them since 2004 while with Texas.

Dickey will try to cool off Carlos Quentin, who had his fifth consecutive multi-hit game on Tuesday. Quentin is hitting .588 (10-for-17) with three homers, two doubles and six walks in the last five games.