CHICAGO (AP) _ Sammy Sosa, returning to the lineup after missing three games with a sprained thumb, continued his long-ball binge with two homers as the streaking Chicago Cubs beat the slumping Florida Marlins 10-2 Monday night.

Sosa hit a two-run shot in the first and a three-run homer in the eighth, his 14th and 15th this year. It was the third time in his last four games that Sosa has hit two homers.

Henry Rodriguez hit a two-run homer in the first and an RBI double in the fifth as the Cubs won their fourth straight and handed the Marlins their sixth consecutive loss.

Jeremi Gonzalez (4-5) ended a personal three-game losing streak, giving up two runs and five hits in 7 2-3 innings.

Ryan Dempster (0-1) lasted 1 1-3 innings in his first major league start, giving up five runs, four hits and three walks. The 21-year-old rookie had previously made two relief appearances for the Marlins.

Dempster walked Mickey Morandini with one out in the first before Sosa hit his first homer of the game. Mark Grace walked and Rodriguez followed with his 12th homer of the season to make it 4-0.

Brant Brown hit a ground-rule double in the second that got stuck in the ivy-covered outfield wall in left. Morandini then singled home Brown, and Dempster struck out Sosa before being pulled.

Todd Zeile, acquired from Los Angeles with Mike Piazza, hit his first homer since joining the Marlins and eighth this year leading off the fifth. Cliff Floyd then doubled and scored on Ryan Jackson's single to make it 5-2.

Rodriguez hit an RBI double in the fifth off Kirt Ojala to make it 6-2. Brown added an RBI single in the sixth.

Notes: Morandini singled in the second to extend his hitting streak to 12 games, equaling his career high set in 1993. ... Dempster is the sixth rookie starter this season for the Marlins, joining Joe Fontenot, Jesus Sanchez, Brian Meadows, Eric Ludwick and Rafael Medina. Florida has used 14 rookie pitchers this season and 21 different pitchers overall. ... Dempster was 4-3 with a 3.22 ERA for Double-A Portland this season.