Rickie Weeks started the go-ahead rally in the opener, then provided most of the offense in the second game.
Weeks scored on Prince Fielder's 13th-inning single as Milwaukee beat host Florida, 3-2, in the completion of a suspended game. He then homered, tripled and scored three runs in a 5-2 victory in last night's scheduled game.
Milwaukee had lost nine in a row to the Marlins before winning two straight.
Tuesday's game was suspended with the score 2-2 after 10 innings and three rain delays that totaled 1 hour, 42 minutes. Before this year, it would have become an official tie game and replayed from the start. But under a rules change made during the offseason, it was picked up where the teams left off.
"It's good rule, it really is," Florida manager Fredi Gonzalez said. "I would have hated to come out here with the way the pitching is and played two games."
Fielder had three singles, a double and three walks to reach base seven times in the opener. He tied the team record set by Kevin Reimer, who was 6-for-6 with a walk against Oakland on Aug. 24, 1993.
"He goes out there and does his part," Milwaukee manager Ned Yost said. "He tries to do his business and not carry too much of the load."
Renyel Pinto (0-1), who lost in his first major league decision, relieved to start the 13th and walked Rickie Weeks leading off. Weeks advanced on Craig Counsell's sacrifice and J.J. Hardy's groundout, then scored on Fielder's hit to right.
"That game was like getting all your teeth pulled out," Yost said. "The guys persevered and stayed after it. They found a way to get it done."
Elmer Dessens (1-0) pitched a scoreless 12th for his first victory for the Brewers.
In the second game, Dave Bush (1-1) allowed one run and 10 hits in six innings, and Francisco Cordero pitched the ninth for his third save. Sergio Mitre (0-2) allowed four runs and 10 hits in six innings.
In other games:
* At Atlanta, Andruw Jones and Chipper Jones homered in the same game for the 56th time, and the Braves beat Washington, 8-3. At 7-1, the Braves are off to their best start since their World Series win of 1995.
* At Pittsburgh, pinch-hitter Chris Duncan homered in the ninth inning, giving St. Louis a 3-2 victory over the Pirates and a three-game sweep. Cards third baseman Scott Rolen was out of the lineup for a second day in a row with back spasms.
* At Phoenix, Josh Hamilton homered for the second straight game and Javier Valentin hit a go-ahead two-run double in the seventh inning as Cincinnati beat Arizona, 3-2.
* At San Diego, Greg Maddux (1-1) earned his first victory with the Padres, tossing six shutout innings in a 4-0 victory over San Francisco.
* At Los Angeles, Brad Penny (2-0) allowed two hits over 6 1/3 innings and Nomar Garciaparra hit a tiebreaking two-run single, leading the Dodgers to a 3-0 victory over Colorado.