Hammel (3-1) allowed just one run and four hits in seven innings to lower his ERA to 2.60.
Olt still is batting below .200 for the season (.195), but has four homers and nine runs batted in.
The Cubs, who've won three of four, have won back-to-back games for the first time this season. They last won consecutive games on Sept. 9 and 10 of last season against the Cincinnati Reds. Their last consecutive home wins came on Sept. 4 and 6 against Miami and Milwaukee.
Brandon McCarthy (0-4) managed to lower his ERA from 7.11 to 6.23. He allowed five runs — one earned — and seven hits in five innings.
