Rookie Javier Baez hit two more homers and drove in four runs Thursday, leading the Chicago Cubs over the Colorado Rockies 6-2.
Along with his home runs, the Cubs' 21-year-old prized prospect had an RBI single to back rookie Kyle Hendricks (3-1).
Baez homered in his major league debut Tuesday, delivering a game-deciding shot in the 12th inning on the day he was promoted from the minors.
Baez led off the sixth inning with a shot down the left-field line off starter Yohan Flande (0-4). Baez hit a two-run shot off reliever Juan Nicasio into the Colorado bullpen in right in the eighth.
Castro followed Baez's shot in the sixth with his 12th home run. It was the fourth time this season Chicago has hit back-to-back homers.
Hendricks pitched a career-high eight innings after the start of the game was delayed 39 minutes because of rain.
Hendricks has pitched into the seventh innings in four of his five career starts and has allowed more than two runs in just two games.
The 24-year-old righty was sharp against the Rockies, allowing just two runs and six hits and striking out four. He didn't allow a runner until Charlie Blackmon's leadoff single in the fourth.
After Baez and Castro gave Hendricks a three-run cushion in the sixth, the Rockies scored on Corey Dickerson's RBI single in the bottom half. Hendricks retired the last seven batters he faced.
Justin Morneau and Wilin Rosario had two hits each for the Rockies, who have lost six of their last seven.
The Cubs took a 2-0 lead against Flande with RBI singles by Arsmendy Alcantara in the second and Baez in the third. Colorado cut the lead in half on Justin Morneau's RBI single in the fourth.
Flande is still looking for his first career win despite two solid outings against Chicago. He struck out a career-high eight in a 4-1 loss to the Cubs on July 28 and lasted six innings Thursday.