Cueto (14-5) hasn't lost since July 3, beating the Padres twice in his winning streak. He allowed eight hits and four runs while walking one and striking out eight Thursday. The 14 wins by Cueto ties him for the most in the major leagues.
The Reds sent 12 batters to the plate in the second. The first five reached with hits, including a two-run home run by Todd Frazier and an RBI double by Ryan Hanigan. Jay Bruce added a two-run single and the last run in the rally came on a balk.
All the runs were charged to Padres' starter Ross Ohlendorf (3-2), who allowed six runs on six hits and three walks. He also struck out three but was pulled after 1 2/3 innings.
Eddy Rodriguez hit a home run in his first major-league at bat and Chase Headley singled in a pair of runs in the San Diego third.
The Padres made the score 6-4 in Cameron Maybin's sixth home run of the season in the fourth but the Reds added two runs in the bottom of the inning with a rally that included an error, a walk, a force out and two singles. Bruce scored on an eighth-inning fielder's choice from Todd Frazier, who had three RBI, to complete the scoring.