MILWAUKEE -- After the San Francisco Giants' frustrating weekend in Philadelphia, the last thing they wanted was to get off to a slow start early against the Brewers in Milwaukee.

But, sure enough, two batters into the first inning, the Giants were in trouble again. When Orlando Calixte's attempt to hit the cutoff man on a routine sac fly sailed past catcher Buster Posey and lodged in between the netting and advertising behind home plate, it could have been the start of an ugly night for Jeff Samardzija and the Giants.

Instead, Samardzija took a deep breath, locked in and went back to work. He retired the next 18 batters and gave his offense time to find its own rhythm as the Giants took the series opener 7-2 at Miller Park.

"I liked how I was warming up and I liked some of the pitches I had made," Samardzija (2-7) said. "I didn't like the pitch to (leadoff batter) Eric Sogard, but we just kept pitching. There wasn't too much reason to panic. It was early in the game and I was just trying to get some outs."

Samardzija struck out 10, while allowing two runs (one earned) on six hits with no walks in 7 2/3 innings.

Joe Panik got San Francisco on the board with an RBI single in the fourth, and Eduardo Nunez tied the game at 2 with a solo home run in the fifth inning, his fourth of the season.

However, it was Aaron Hill who provided the big hit, driving in a pair with a pinch-hit double in the eighth that broke a 2-2 tie.

"That's not the way we wanted to start here but what a job (Samardzija) did," Giants manager Bruce Bochy said. "He just pitched a terrific game. He had good command, good velocity. Great changeup, cutter too. Good for him to get a win. He should have a few more wins. Good we found a way to score some runs for him."

Junior Guerra only lasted five innings for the Brewers, allowing two runs (one earned) on seven hits with three walks while striking out two, but once again, the Brewers' bullpen couldn't come through in the clutch.

Rob Scahill (1-2) worked a quick seventh but got into trouble in the eighth, allowing a leadoff single to Brandon Belt. Posey grounded into a force at second, but Brandon Crawford drew a walk and Scahill gave Panik a free pass, setting the stage for Hill's big moment.

"We've got to find some guys to get some outs down there," said Brewers manager Craig Counsell, whose relievers lead baseball with 17 losses this season. "Rob did a nice job. He was a pitch away from getting out of the inning but it was a big spot where you've got to make a pitch."

The Brewers still had a chance heading into the ninth, only down two, but struggling right-hander Neftali Feliz, who had been demoted from the closer's role on May 12, let the game get out of hand quickly, loading the bases without retiring a batter.

An error on center fielder Brett Phillips didn't help the situation, but Belt made it a 5-2 game with an RBI single and, after Posey drove in another on a groundout, Feliz reloaded the bases with an intentional walk. Nunez scored on Hunter Pence's groundout to put the Giants up five before Feliz finally got out of it.

"(Neftali) is getting stuck in these innings for sure," Counsell said. "He's falling behind with his best pitch and that's what's really hurting him. His fastball, that's his pitch. He's going to rely on it. They know it's coming. I think ahead in the count is where it has to be."

NOTES: Milwaukee placed 3B Travis Shaw on the paternity list and selected the contract of OF Brett Phillips from Triple-A Colorado Springs. Phillips was in the starting lineup for his major league debut and recorded his first big league hit with a leadoff single in the eighth. ... Giants OF Hunter Pence made his first start since returning from the 10-day disabled list and went 1-for-4. ... Brewers manager Craig Counsell said RHP Matt Garza was feeling much better Monday and was likely to make his next scheduled start Thursday against the Giants. Garza sustained a chest contusion Sunday when he collided with 1B Jesus Aguilar while trying to make a play at first base. ... The Giants improved to 16-1 this season when leading after eight innings. ... Brewers starters are 5-1 with a 1.36 ERA over their last 11 games, striking out 62 with just 22 walks in 66 1/3 innings of work.