The NL West-leading Padres got all their 13 hits from singles, winning their seventh straight home game and for the 11th time in 13 games overall.
San Diego starter Wade LeBlanc (2-0) got a career-high three hits, and was also impressive from the mound, striking out six and walking none in 6-1/3 scoreless innings.
After struggling early against Milwaukee starter Doug Davis (0-3), including taking four straight called third strikes, the Padres broke through with four runs on four hits in the fourth. The first four Padres batters reached base and scored.
In St. Louis, rookie David Freese homered, doubled and drove in six runs as St. Louis sent Atlanta to its ninth straight loss.
The Braves wrapped up an 0-7 road trip, their first winless swing of seven or more games since 1949 when the franchise was located in Boston.
Starter Adam Wainwright (4-1) worked six solid innings as the Cardinals completed a four-game sweep - their first sweep of Atlanta since 1993.
Atlanta starter Jair Jurrjens (0-3) strained his left hamstring and lasted only one inning.
In Chicago, Ian Kennedy pitched eight strong innings for his first victory in 21/2 years, steering Arizona past Chicago.
Kennedy (1-1) allowed only one run in the first seven innings as the Diamondbacks built a 13-1 lead before giving up Kosuke Fukudome's grand slam in the eighth.
Adam LaRoche drove in five runs with two homers and a double, while Kelly Johnson and Chris Snyder also connected for Arizona, which leads the majors with 33 homers.
Johnson, who has an NL-high nine homers and has gone deep six times in the past seven games, also had three singles.
Cubs starter Ted Lilly (1-1) surrendered six runs in five innings in his second start since shoulder surgery.
In Houston, Bronson Arroyo pitched 6 2-3 strong innings for his first win of the season, helping Cincinnati down Houston.
Arroyo (1-2) allowed two runs with seven strikeouts to bounce back from his last start, when he allowed eight runs in three-plus innings.
Joey Votto hit a first-pitch two-run homer as the Reds won their fourth straight and inflicted a third successive defeat on the Astros.
Houston starter Roy Oswalt (2-3) gave up eight hits in seven innings in his first start since helping clear up after the family home was destroyed in a tornado.
In Los Angeles, Pittsburgh pushed Los Angeles to a fifth straight loss.
Dodgers starter Clayton Kershaw (1-1) walked his first two batters of the game, and both scored when Ryan Doumit's sinking liner got past Dodgers centerfielder Matt Kemp as he tried to backhand it on the short hop.
Pittsburgh starter Brian Burres (1-1) pitched 5 1-3 scoreless innings to lift the Pirates to a third straight win.
