Updated

Buster Posey and the surging San Francisco Giants look to complete their first sweep of the season when they take on the Milwaukee Brewers this afternoon in the finale of a three-game set from Miller Park.

Posey has homered in back-to-back games and owns six RBI in that span. He belted a three-run homer in the series opener on Monday, then cracked a two- run shot in last night's 6-4 win. Joaquin Arias also clubbed a two-run home run for the Giants, winners in eight of their last 11 games. The Giants needed 14 innings to dispose of Milwaukee in the series opener.

"He looked fresh," Giants manager Bruce Bochy said of Posey's game after catching 12 innings on Monday. "He likes this park, he sees the ball well here."

Giants starter Matt Cain allowed four runs on 11 hits and did not issue a walk while fanning eight to earn his first win against the Brewers since the 2009 season. Sergio Romo tossed a perfect eighth and Santiago Casilla worked around a walk in the ninth inning to earn his 11th save of the season.

Aubrey Huff was back in the starting lineup after a bout with anxiety disorder and finished 0-for-3 with a run scored. Huff hadn't started since April 21 in New York.

"The two balls I did hit, I just missed them," Huff said after the Giants moved a season high three games over .500. "That's a good start for sure."

San Francisco is scheduled to visit Miami for four games after tonight and hopes Barry Zito can complete the first sweep at Miller Park since a four-game series from July 5-8, 2010. Zito has won two straight starts and barely got by his former Oakland team in last Friday's 8-6 win, as he was reached for four runs and five hits in 5 1/3 innings.

Zito improved to 3-1 on the season through eight starts and has an ERA of 3.00, spanning 48 innings pitched. The lefty and 2002 AL Cy Young Award winner has made eight career starts against Milwaukee, going 2-3 with a 5.48 ERA.

Milwaukee will put the finishing touches on a six-game homestand (1-4) tonight and has lost eight of its last 10 contests.

Rickie Weeks drove in two runs, Norichika Aoki went 2-for-4 with an RBI and a run scored and both Aramis Ramirez and Jonathan Lucroy had two hits and scored a run in a losing cause. Shaun Marcum was banged around for six runs and five hits in six innings to suffer the loss.

"I made three mistakes, and they hit them," Marcum said. "The walks obviously hurt me, but those guys scored, and other than that, it's just locating the ball when I fall behind in the count and making good pitches."

Reigning NL MVP Ryan Braun, who left Monday's game with a tight right groin, was back in the lineup last night and went 1-for-4 with an RBI.

"Nice to have him in the lineup," Brewers manager Ron Roenicke said. "It made a difference last night when he's not in that lineup going into extra innings, trying to get one run, and he's not out there."

The Brewers will begin a seven-game trek against the Diamondbacks and Dodgers on Friday, and will turn to starting pitcher Marco Estrada tonight. Estrada is 0-3 with a 4.63 earned run average in 10 games (5 starts) this season and is 0-3 in his last four appearances. He gave up four runs in five innings of an 11-3 loss to Minnesota last Friday and has allowed 15 runs in his previous four trips to the mound.

Estrada is 0-2 at Miller Park this season and has no record or ERA in two career relief appearances against San Francisco (1 2/3 innings).

The Brewers dropped two of three to the Giants from May 4-6.