The veteran right-hander helped his cause with an RBI single in the bottom of the fifth-inning when Chicago scored all of its runs.

Also in the inning, Ryan Theriot hit a sacrifice fly and Derek Lee belted a two-run double.

Aramis Ramirez had three of Chicago's 13 hits and three players had two for the NL Central Division-leading Cubs, who took three contests during the four-game series.

Dempster (5-1) walked one batter and fanned a career-high 12.

Brian Giles had three of the Padres' six hits.

The losing pitcher, former Cub Greg Maddux (3-4), gave up four earned runs and 11 hits in 4 1/3 innings.

Overall, San Diego has lost eight of its last 11 games.