Carlos Gomez broke a scoreless tie in the ninth inning with an RBI single and Jeff Bianchi added a two-run double as the Brewers won 5-0 in the series opener.
The St Louis Cardinals were no match for the Pittsburgh Pirates, who came through 9-2 - with Francisco Liriano allowing one run over seven dominant innings.
The Cleveland Indians maintained their hot streak, a 3-2 win over the Chicago White Sox giving them a fifth successive victory.
Andrelton Simmons' walk-off treble in the 10th inning sealed a fourth successive win for the Atlanta Braves, 9-8 against the Colorado Rockies.
Daniel Murphy drove in three runs as the New York Mets snapped a five-game skid with a 6-5 win over the Miami Marlins, while the Texas Rangers ended their losing stretch at four with a 4-3 defeat of the Los Angeles Angels.
Tampa Bay Rays regained pole position in the American League East with a 2-1 defeat of the Boston Red Sox, AJ Griffin allowed just four hits in the Oaklands Athletics' 9-4 win over the Toronto Blue Jays, while Chris Denorfia's two-run, pinch-hit homer off Aroldis Chapman in the bottom of the ninth inning gave the San Diego Padres a 2-1 victory over the Cincinnati Reds.