OAKLAND, Calif. -- The Milwaukee Brewers ended a discouraging road trip with an uplifting victory Wednesday at the Oakland Coliseum.

Junior Guerra pitched seven strong innings, Scooter Gennett and Kirk Nieuwenhuis homered, and the Brewers ended their four-game losing streak with a 4-2 victory against the Oakland A's.

The Brewers finished 2-7 on their nine-game road trip. They went 0-3 against the San Francisco Giants and 1-3 against the Los Angeles Dodgers before salvaging a 1-1 split with the A's.

"We needed this one," Milwaukee manager Craig Counsell said. "There's been tough games this year that we've come back from, but this was a tough trip, and to finish it on this note in a well-played game and well-pitched game, it's important."

Guerra, a 31-year old rookie from Venezuela, gave up two runs on five hits in his 10th career major league start. He struck out eight and walked one. Guerra (4-1) went 0-1 with four no-decisions over his previous five starts before beating the A's.

From 2011 to 2014, Guerra pitched in the Mexican League, in Italy and for the Wichita Wingnuts of the independent American Association. Now he owns a 3.67 ERA and four wins in the big leagues.

"Right now, nothing's guaranteed," Guerra said. "All you can do is keep working hard, keep doing your thing, keep doing your job and give your team a chance to win."

Counsell had enough faith in Guerra to let him pitch to left-handed pinch hitter Stephen Vogt with two outs and a runner on second in the seventh inning with the Brewers clinging to a 3-2 lead. Guerra struck out Vogt swinging on a split-finger fastball.

"I wanted Junior out there for Stephen Vogt because I thought he's kind of earned that," Counsell said. "He's pitched like he's going to handle that situation. He came back and he came through, and he made big pitches in that at-bat."

Gennett went 3-for-5 with a two-run shot in the fifth inning, and Nieuwenhuis had a solo home run in the eighth. Martin Maldonado had three hits and Ramon Flores two, including a double, for the Brewers.

A's rookie-right hander Daniel Mengden (0-3) gave up three runs on seven hits over six innings in his third career major league start. Mengden struck out nine and walked one. Through three games and 18 innings, he has allowed only six earned runs, but he is still searching for his first big-league win.

"It's not frustrating," Mengden said. "I'm just going out there and trying to give our team a chance to win. We'll get it eventually."

A's manager Bob Melvin said of Mengden, "He pitches good, but we're just not giving him any support. He knows we think he's good, and he is."

Coco Crisp went 2-for-3 with a solo home run and a double for Oakland, which managed just five hits.

The A's, who went 3-6 on their nine-game homestand, scored only 12 runs over their past six games.

Crisp gave the A's a 1-0 lead in the fourth inning, leading off with a home run into the right field seats off Guerra. The blast was Crisp's sixth of the season.

Milwaukee answered with three runs in the fifth off Mengden. With one out, Flores hit an opposite-field double off the left field fence, then took third on Crisp's throwing error. Yadiel Rivera brought Flores home with a bunt that Mengden got to quickly but couldn't field cleanly.

Then with two outs, Gennett launched an opposite-field, two-run homer to left-center field, his seventh shot of the season.

Gennett hit .343 with two home runs and six RBIs on the road trip.

"I feel good," Gennett said. "Healthy. I'm seeing the ball well. the only times I've gotten out have been swinging at bad pitches."

Oakland cut the Brewers' lead to 3-2 with a run in the seventh. Yonder Alonso singled, moved to second on a groundout and scored on Max Muncy's sharp single to right.

Nieuwenhuis homered off reliever Liam Hendriks with two outs in the eighth, hitting an opposite-field shot to left-center.

Brewers right-hander Tyler Thornburg got the final four outs for his second save of the season.

"I think the difference was we added some runs on late," Counsell said. "We got Scooter's home run, and then Kirk's home run just gives those guys a little bit of breathing room."

NOTES: Brewers RHP Jeremy Jeffress was not available to pitch out of the bullpen because of pinkeye. ... Athletics LHP Rich Hill (left groin strain) will make a rehab start for Class A Stockton on Monday. He threw a bullpen session Tuesday and will throw another one Friday. A's manager Bob Melvin said that, barring a setback, Hill likely will need one rehab start before rejoining the major league rotation. ... Oakland SS Marcus Semien started his 71st consecutive game this season. He is the only Oakland player to appear in every game this year. ... Brewers SS Jonathan Villar was out of the starting lineup for just the fourth time this season. "Just a physical break and a mental break," manager Craig Counsell said. "Just recharge the battery." Yadiel Rivera started in Villar's place. ... Brewers C Jonathan Lucroy started his third straight game at designated hitter as Counsell continued giving him a chance to rest his legs. Including off days Monday and Thursday, Lucroy will have gone five straight days without catching before the Brewers open a homestand Friday against Washington.