Corbin Burnes experienced a happy homecoming, Jace Peterson stroked three hits and the visiting Milwaukee Brewers opened a four-game series among National League division leaders with a 3-1 victory over the San Francisco Giants on Monday night.

Burnes helped his own cause with an RBI single and Brad Boxberger pitched out of a seventh-inning jam for Milwaukee. The Brewers moved 9 1/2 games ahead of the second-place Cincinnati Reds in the NL Central and pulled within 4 1/2 of the Giants in their duel for the best overall record in the league.

Brandon Crawford drove in the only run for the Giants, who used seven pitchers in what turned into a bullpen game after listed starter Johnny Cueto couldn't go because of an illness.

A product of Saint Mary's College across the bay, Burnes (9-4) pitched into the seventh inning in his first career start in San Francisco.

In running his unbeaten streak to 15 straight starts, he took a 2-0 lead into the seventh before allowing a double to Brandon Belt and single to Kris Bryant.

Boxberger came on and immediately served up an RBI single to Crawford but then retired the next three Giants, the final two with both the potential tying run at third base.

Burnes was charged with one run on four hits in six-plus innings. He struck out nine and did not issue a walk.

Protecting a 3-1 lead in the bottom of the eighth after the Brewers had tacked on in the top of the inning on a Luis Urias sacrifice fly, Devin Williams pitched around a one-walk in a scoreless inning.

In the bottom of the ninth, Bryant led off with a double off the Brewers' All-Star closer, Josh Hader. However, the left-hander got the next three men in order for his 28th save, locking down the Brewers' second straight win after a three-game losing streak.

Burnes' run-scoring hit came in the second inning, scoring Peterson, who had walked.

Milwaukee had already scored one in the first on a double by Christian Yelich and a single by Omar Narvaez.

Peterson also doubled for Milwaukee, which out-hit the Giants 9-6.

Belt and Bryant had a double and single apiece for San Francisco, which was opening a seven-game homestand in which it will see the NL West second-place Los Angeles Dodgers visit for three at the end of the week.

Emergency Giants starter Jose Alvarez (4-2) took the loss after allowing two runs and four hits in 1 2/3 innings. The left-hander walked two and did not record a strikeout.

--Field Level Media