The Pirates dropped seven games during a season-long 10-game road trip and had lost 10 of 13 overall before withstanding solo homers by Alfonso Soriano and Geovany Soto to win for the first time in their last four home games.
The Cubs, coming off a three-game weekend sweep of Arizona, fell to 13-14 while failing to break .500 for the first time this season. They had won 10 of their last 14 against Pittsburgh, and Dempster was 3-0 with a 3.73 ERA in five starts against them since 2008.
With the Cubs stranding 12 runners, the Pirates won for only the second time in 16 games when they scored three runs or fewer. They are 9-1 when they score four runs or more.
Paul Maholm (2-2) got the decision despite allowing the two solo home runs and six other hits over six innings. Evan Meek pitched out of a jam in the seventh before Joel Hanrahan pitched a scoreless eighth. Octavio Dotel, who came in with a 10.61 ERA, finished up for his fourth save in six opportunities after being scored upon in six consecutive appearances.
The Pirates trailed 2-1 after Soriano hit his seventh homer - and fifth in four games
- in the fourth inning and Soto added a two-out drive in the sixth, his fourth. Soriano, coming off a two-homer game Sunday, went deep for the fourth consecutive game.
Dempster (2-2) got the first two batters in the sixth ahead of Garrett Jones' infield single. Church
- starting in center field only because Andrew McCutchen sat out with a sprained right ankle
- followed by hitting a line drive off the first row of seats in right field. Church hadn't homered since Aug. 7.