Miami had a runner on first with one away in the eighth when the contest was halted and it was eventually called after a lengthy delay.
It was a 1-1 game until the Cubs batted around in the seventh. Alfonso Soriano led off the inning with an infield single against Josh Johnson (5-7), went to second on a wild pitch, moved to third on a groundout by Bryan LaHair and scored on Soto's single.
James Russell (3-0) got the win by working the seventh, from which he escaped after giving up a hit and a walk. It was Russell's 46th appearance of the season.
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