Chicago (55-36) went 4-6 on its longest road trip of the season, although the swing concluded with a 7-1 win over St. Louis on Sunday. While the Cubs are 20-26 on the road this season, their major league-best 35-10 home record has propelled them to the top of the NL.

After winning Tuesday's series opener 7-3, Chicago defeated the Reds 5-1 on Wednesday to move 4 1/2 games ahead of the second-place Cardinals and five games up on third-place Milwaukee.

The Reds (43-49), who came to Chicago winners of seven of nine, are now trying to avoid being swept at Wrigley for the first time since May 22-24, 2001.

The Cubs have won Thursday's starter Ted Lilly's last seven outings at Wrigley.

Lilly (9-5, 4.47 ERA) looks to become the third straight Cubs pitcher to earn his 10th win of the season after All-Stars Ryan Dempster and Carlos Zambrano reached that mark Tuesday and Wednesday, respectively.

Reaching the 10-win plateau before the All-Star break didn't initially look likely for Lilly, who opened the season 0-3 with a 9.16 ERA in his first four starts. The left-hander has settled down since then, though, going 9-2 with a 3.54 ERA in his last 15 outings.

On Saturday, Lilly allowed two runs in six innings of a 5-4 loss at St. Louis, but was not a factor in the decision.

Lilly's only start of the season against the Reds came early in the year when he was scuffling. On April 17, he gave up five runs and six hits in six innings of a 9-2 home loss.

Cubs All-Star third baseman Aramis Ramirez had another big night at the plate Wednesday, as he hit his 16th homer in the sixth inning to break a 1-all tie. Ramirez is 7-for-11 with two home runs and eight RBIs after being hitless in his previous 28 at-bats.

"Everybody goes through a tough stretch like that, but I feel pretty good right now," he told the Cubs' official Web site.

The Reds, who managed just two hits on Wednesday, scored their lone run on Adam Dunn's 23rd homer of the season. The Cincinnati slugger has five home runs in his last 10 games, and has four homers in eight games against the Cubs in 2008.

Bronson Arroyo (6-7, 5.82) looks to help the Reds avoid the sweep when he takes the hill in the series finale.

After getting pounded for 10 runs and 11 hits in one inning of work in a 14-1 loss to Toronto on June 24, Arroyo has regrouped, allowing two runs and 10 hits over 12 innings to win his last two starts. On Friday, the right-hander gave up five hits in six innings of a 3-0 victory over Washington.

He is looking to win three straight starts for the first time since winning four in a row Sept. 1-15, 2006. The last victory of that winning streak also was his last win over the Cubs.

Arroyo, who has yet to face Chicago in 2008, went 0-3 with a 3.58 ERA in five starts against the Cubs last season after going 4-0 with a 1.01 ERA in five starts versus them in 2006. He is 4-6 with a 3.24 ERA in 13 career starts versus Chicago.