SAN FRANCISCO -- The Milwaukee Brewers never made it easy on Johnny Cueto during their seven-game losing streak to the former Cincinnati Reds ace.

That all changed during win No. 8 Wednesday.

Aided by a Brewers comedy of errors in the field that helped the San Francisco Giants stake their right-hander to a big lead, Cueto coasted through seven innings in a 10-1 victory that capped a three-game sweep.

"When you have that big of a lead, you can relax and pitch your game," Cueto said after the Giants staked him to an 8-0 advantage on the strength of four-run third and fourth innings. "It builds my confidence when I see my teammates score runs for me. Hopefully we can continue that."

Gregor Blanco, Joe Panik, Matt Duffy and Angel Pagan had three hits apiece as the Giants beat the Brewers for the fifth time in six meetings this season.

The series sweep was San Francisco's fifth of the season and pushed the National League West leaders 15 games above .500 for the first time this year.

"It was nice to see the offense clicking today," Giants manager Bruce Bochy said. "That could be more like us."

Cueto pitched a 2-1 win over the Brewers on April 5 in his Giants debut. The paltry offensive support was consistent with what he got from the Reds, who totaled just 24 runs in the first six games of his streak against the Brewers.

He demonstrated Wednesday he can be equally effective on the mound no matter how much run support he gets.

Cueto (10-1) limited the Brewers to one run and seven hits in seven innings. He walked one and struck out nine.

"He was Johnny today," Bochy said. "We've been playing a lot of tight games. It was nice to be able to take him out after seven and give him a breather."

Cueto hasn't lost to Milwaukee since Aug. 2, 2012. Only three pitchers -- Randy Johnson (14), Jose Lima (10) and Dave Stewart (nine) -- had longer winning streaks against the Brewers.

Milwaukee has scored a total of 11 runs in 59 innings against Cueto during his streak.

"We've been unfortunate enough to run into some pretty good pitching this series," said Brewers catcher Jonathan Lucroy, who had two of Milwaukee's eight hits. "We just couldn't string enough hits together really to do any damage. On top of that, we didn't play defense as good as we should have. We didn't pitch as good as we should have. We have to be better in everything."

The Giants took advantage of shoddy Brewers defense to put together their back-to-back, four-run innings against Milwaukee starter Jimmy Nelson (5-6).

It began in the third after a leadoff single by Blanco.

Panik bunted back to Nelson, who threw wildly to first base for the second of Milwaukee's season-worst four errors in the game.

Buster Posey drove in the first two runs with a single and Duffy made it 3-0 when he added an RBI single.

A fourth run scored when Brewers third baseman Hernan Perez overthrew first base, allowing Duffy to score.

Blanco also got the four-run fourth rolling with a double. He scored on Panik's RBI single.

After a one-out single by Posey, Nelson had a chance to get out of the inning when he struck out Duffy, but Perez couldn't handle Martin Maldonado's throw on a steal attempt by Panik, allowing a second run to score.

Pagan's run-scoring double made it 7-0 and ended Nelson's day. Jarrett Parker's RBI single off Jhan Martinez capped the big inning.

Blanco was 3-for-6 in his return to the leadoff spot as Denard Span was given the day off. That's 6-for-his-last-11 after going hitless for 27 at-bats, a result, he said, of a cortisone shot he took in his right shoulder last month.

"I saw myself (batting first) on the lineup card and said, 'Yes,'" he admitted. "I feel more like myself every time I'm in the leadoff spot."

Nelson was charged with eight runs (six earned) in a season-low 3 2/3 innings. He allowed eight hits and three walks, striking out two.

"I fell behind some guys, walked a couple guys, but it was also a couple bad breaks there," said Nelson, who is 0-3 with a 9.69 ERA in his last three starts. "It's very frustrating for me. The last three (starts) have been completely unacceptable. It's just been brutal."

Ramiro Pena put the finishing touches on the scoring with a two-run single in the eighth.

Pagan finished with two doubles among his three hits. The Giants out-hit the Brewers 16-8 in winning for the 14th time in their last 18 home games against the NL Central club.

The sweep allowed the Giants to finish a 6-2 homestand. They've won 11 of their last 13 home games.

A disastrous day at the ballpark for the Brewers also included right fielder Ramon Flores tripping over the bullpen mound while chasing a foul fly ball and Jonathan Villar getting picked off first base by Cueto, resulting in the leadoff hitter's major-league-leading eighth caught stealing of the season.

"We didn't do ourselves any favors," Brewers manager Craig Counsell understated. "We didn't play a good defensive game at all. Just too many mistakes, too many outs we left out there."

Alex Presley's fifth-inning single scored Perez with the Brewers' only run.

NOTES: The Giants hit .389 (42-for-108) in the three-game sweep. ... Giants RHP Johnny Cueto is now 6-0 with a 1.04 ERA in his last eight starts. ... Giants 1B Brandon Belt, pulled from Tuesday's game after getting hit by a pitch on the right ankle, was kept out of the lineup. ... The Brewers' four errors were their most since they had four on June 21, 2014. ... Brewers LF Ryan Braun did not play. He had struggled in previous at-bats against Cueto, going 10-for-47 (.213) with 14 strikeouts. Only St. Louis RHP Adam Wainwright (20) has struck out Braun more often in his career. ... With Braun, the club's No. 3 hitter, out of the lineup, C Jonathan Lucroy moved up a spot to third and CF Kirk Nieuwenhuis batted cleanup for the first time in his big league career. ... Brewers manager Craig Counsell announced that RHP Michael Blazek (right elbow impingement) came through an injury-rehab outing in good shape and is scheduled to make one more appearance for Triple-A Colorado Springs on Thursday night. He could be reinstated from the 15-day disabled list by the weekend.