Milwaukee comes to New York having won three of four at home against Los Angeles to up its lead in the Central to 6 1/2 games over the second-place St. Louis Cardinals.
The Brewers are 31 games over .500 (47-16) at home, but 10 games under (26-36) in 62 games away from Miller Park. They suffered a rare home loss in Thursday's finale with the Dodgers, as Clayton Kershaw went eight strong innings to help LA avoid a four-game sweep with a 5-1 win.
Marco Estrada (3-8) was handed the loss despite giving up just one run and three hits over five innings for the Brewers, who had a six-game winning streak stopped. Prince Fielder drove in the lone run with a sacrifice fly in the ninth.
Gee (11-4) allowed just one run on five hits and four walks while fanning five to earn the win.
Angel Pagan had three RBI for the Mets, who won a series in San Diego for the first time since 2002.
New York is third in the NL East, 20 1/2 games behind runaway leader Philadelphia and 12 in back of wild card-leading Atlanta.
The Brewers will send Shaun Marcum to the mound tonight and he has won three straight decisions. Marcum hasn't lost since late June.
The 29-year-old Missouri native won 13 games for the Toronto Blue Jays while making 31 starts and has instantly become a success with the Brewers, who have won five of his last six starts while outscoring foes, 27-14.
He tossed 7 2/3 innings of one-run ball with five strikeouts in Milwaukee's 2-1 defeat of Pittsburgh on Aug. 14, five days after allowing three runs in six innings of the Brewers' 5-3 win at St. Louis.
Marcum got a no-decision in one career meeting with the Mets, but tossed six scoreless innings of two-hit ball with four strikeouts and no walks.
New York replies with 27-year-old righty Mike Pelfrey, who's not won since July 27 and comes in off his first relief appearance of 2011.
The Wichita State product tossed one-third of an inning at San Diego on Aug. 16, three days after he was removed from a start against Arizona after four innings following a Gerardo Parra line drive to the right elbow in the fifth.
Pelfrey suffered a contusion to the elbow and X-rays were negative.
His last win came against the Cincinnati Reds, as he went the nine-inning distance and allowed seven hits in an 8-2 triumph.
He's split two career decisions in four starts against the Brewers while posting a 3.12 ERA in 26 innings.
The Mets took two of three in Milwaukee in the first meeting between the clubs this year after the Brewers won five of seven in 2010. Former Mets closer Francisco Rodriguez will return to Flushing, NY for the first time since being traded to Milwaukee in July.