MILWAUKEE -- Looking to win three consecutive games for the first time this season, the San Diego Padres got all they needed Thursday night from James Shields and Melvin Upton Jr.

Upton had three hits, including his fourth home run of the season, while Shields worked seven strong innings as Padres beat the Milwaukee Brewers 3-0 in front of a sparse crowd of 17,374 at Miller Park.

Shields (2-5) allowed seven hits and a walk while striking out a season-high nine -- the first time in a year he hit that mark.

"He's been fighting all year, and it really came together tonight for him," Padres manager Andy Green said.

Shields kept the trouble to a minimum. The Brewers put the leadoff batter aboard in four different innings but went 0-for-4 with runners in scoring position.

Domingo Santana and Scooter Gennett opened Milwaukee's first inning with singles, but Gennett got stuck in a rundown trying to advance to second as Santana went to third.

Shields retired the next two to leave Santana stranded, then set down seven of his next eight batters despite having to throw to a new catcher after Derek Norris left the game in the second when he was hit by a pitch.

X-rays were negative, and Norris was diagnosed with a bruised left hand.

Christian Bethancourt took over at catcher, and Shields kept on cruising.

"We kind of briefed each other a little bit," Shields said. "Both our catchers do a great job of doing scouting reports and kind of having good game plans. And 'Betty' does a great job even if he isn't catching that day. He knows the game plan, so it was fine."

The Padres gave Shields a lead in the fourth. Wil Myers led off with a single and scored on a two-out base hit by Upton.

In the seventh, Upton doubled, went to third on a Bethancourt lineout and scored on a Alexei Ramirez sacrifice fly to make it a 2-0 game.

"The opposite-field double, that was my favorite part of the game," Green said. "Melvin got us going all day long. He's been in the middle of a lot of things for us all season long. He's played a lot of good baseball, and it's been great having him in the middle of the order."

The Brewers' offense, meanwhile, endured a lackluster showing at an unfortunate moment. Milwaukee got its best starting pitching performance of the season, an eight-inning, two-run, five-strikeout effort from right-hander Jimmy Nelson.

At only 93 pitches, Nelson (4-3) likely would have stayed in the game, but the Brewers went with a pinch hitter to lead off the eighth. They had two runners on against Brandon Maurer but couldn't cash in. Ryan Braun grounded out to third, ending the threat.

Braun extended his hitting streak to 12 games but came up empty three times with runners in scoring position.

"We had the right guy up there in our scoring opportunities, but it just didn't play tonight," Brewers manager Craig Counsell said. "We had the right guy up there, for sure."

Upton made it a 3-0 game with a home run to lead off the ninth against right-hander Tyler Thornburg.

With Padres closer Fernando Rodney held out after saving both games of a doubleheader Wednesday, Green called on left-hander Ryan Buchter, who earned his first save with a perfect ninth.

NOTES: Milwaukee acquired RHP Jhan Marinez after the game from Tampa Bay and designated LHP Michael Kirkman for assignment. ... With RHP Andrew Cashner (hamstring) being pushed back, the Padres will recall RHP Christian Friedrich from Triple-A El Paso on Friday and give him the start against the Brewers. ... 2B Scooter Gennett returned to the Brewers' roster and starting lineup Thursday, completing a stint on the 15-day disabled list for a strained right oblique that included a short minor league rehab assignment with Class A Brevard County. ... To make room for Gennett on the active roster, Milwaukee optioned INF Yadiel Rivera to Triple-A Colorado Springs, where manager Craig Counsell said he'll play primarily at second base and get regular at-bats that wouldn't be available with the Brewers. ... C Hector Sanchez, acquired off waivers Wednesday from the White Sox, will join the Padres on Friday in Milwaukee. San Diego optioned LHP Keith Hessler to Triple-A El Paso.