Justin Steele breezed through seven shutout innings and the Chicago Cubs scored six runs in the second inning Thursday night, beating Pittsburgh 9-0 and sending the Pirates to their 100th loss of the season.

Steele (4-4) struck out seven and gave up four hits on 76 pitches. The rookie left-hander, who hadn't gone more than five innings in eight major league starts, bounced back after allowing six runs and seven hits against the St. Louis Cardinals on Sept. 24.

Sergio Alcantara drove in three runs, two coming on a homer to right off Miguel Yajure (0-2) that gave Chicago a 3-0 lead in the six-run second. Steele helped his own cause with a single and scored on a groundout by Frank Schwindel, Rafael Ortega took home on a double steal, Willson Contreras had an RBI double and Matt Duffy made it 7-0 with a single.

The Cubs have not announced a starting pitcher for the first of a three-game series at St. Louis on Friday.