Cubs 3, Rockies 1: Alfonso Soriano homered, Anthony Rizzo added a tie-breaking double and Jeff Samardzija pitched into the eighth inning as visiting Chicago claimed the opener of a three-game series.

Samardzija (6-9) struck out six and allowed one run on four hits over 7 1/3 innings, and the Cubs put him in line for the win when Rizzo laced a double to the right-field wall off Edgmer Escalona (1-3) to score Cody Ransom in the seventh. Pedro Strop recorded the final two outs in the eighth to strand two and preserve a 2-1 lead, and Kevin Gregg allowed the winning run to the plate in the ninth before getting a double-play ball from Michael Cuddyer to finish off his 18th save.

Soriano led off the fourth with a solo shot - his team-leading 17th - to center. The Rockies tied it in the bottom of the inning when Dexter Fowler launched a leadoff homer to center and had a chance to get more before Samardzija made an athletic play to tag out Troy Tulowitzki, who was trying to score from third after a first-pitch splitter to Todd Helton squirted past catcher Welington Castillo.

Center fielder Junior Lake went 3-for-4 with a double and a stolen base in his major-league debut for Chicago, which has won seven of its last 10. Darwin Barney plated an insurance run with a double into the left-field corner in the ninth.

Rockies starter Jorge De La Rosa allowed one run on five hits over six innings. Soriano's home run was only the third De La Rosa has allowed in his last 14 starts.

GAME NOTEBOOK: The Cubs placed OF Brian Bogusevic (hamstring) on the disabled list and called up Lake, who doubled on the first major-league pitch he saw in the second inning. … Fowler's home run was his first since hitting a pair June 2 against the Dodgers. … Cubs starters have combined for 58 quality starts, and Chicago is 36-22 in those games.