The Rockies were attempting to improve to 5-0 for the first time. This is the fifth occasion they have won four of their first five.
Starlin Castro also added a solo shot for the Cubs, who entered without a home run this season. Chicago was limited to three runs through the opening three games, but finally erupted at hitter-friendly Coors Field. The Cubs had 12 hits Saturday, which was as many as they had coming in.
Jason Hammel (1-0) allowed three runs and eight hits in six innings against his former team. He also had two singles.
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