Conor Jackson scored the deciding run and Chad Tracy hit a three-run homer for Arizona, which has won six in a row. Juan Cruz (2-0) got the win after hurling a scoreless ninth. Starter Ed Gonzalez lasted seven innings, giving up four runs on six hits with three strikeouts.
Reds starter Kyle Lohse turned in seven innings of four-run, six-hit ball. David Weathers (0-1) gave up the final run to take the loss. Adam Dunn, Josh Hamilton and Brandon Phillips all homered in the Reds' third straight loss.
The game had gone into extra innings deadlocked at 4-4.