Smith had three hits as the Padres finished with a season-high 16 one night after managing just one hit in a win over the Reds.
Ian Kennedy (6-9) pitched six strong innings, giving up one run and seven hits with a walk and three strikeouts to get his first win in nearly a month. Kennedy, who improved to 4-1 in his career against the Reds, was 0-3 with a 6.08 ERA in his last four starts in June.
Quentin's two-run homer in the four-run, seventh inning was the key blow when the Padres extended their lead to 7-1.
Mike Leake (6-7) allowed three runs and 11 hits in 5 2/3 innings.