Together, the duo controls the fate of the Milwaukee Brewers.
Fielder set a franchise record with his 13th homer this month, Hardy drove in two runs -- including the go-ahead tally in the eighth -- and the NL Central-leading Brewers beat the Florida Marlins 4-3 Thursday.
Corey Hart doubled with two outs in the eighth and Hardy followed with a single off reliever Matt Lindstrom (0-2) for his team-leading 46th RBI.
Brewers manager Ned Yost said teams had started the season by pitching Hardy inside while he put together a 19-game hitting streak. Now, they're pitching him away.
"I was trying to pull a lot of outside pitches," Hardy said. "I hadn't been seeing the ball as well as I was earlier. Now, I've gone back not trying to do too much."
Yost said Hardy's go-ahead hit was an example of his hard work paying off.
"J.J. takes what they give him," Yost said. "A beautiful, opposite-field single to win the ballgame for us."
Meanwhile, the humble Fielder continued his torrid pace -- hitting his seventh homer in 11 days.
"I try to make it that simple so I don't get my brain involved," Fielder said. "Just try to use my eyes and see what happens."
Fielder and Hardy have combined to hit .300 with 34 homers and 89 RBI at the one-third mark of the season, helping the Brewers take a 6 1/2-game lead in the NL Central.
"I just try to put the barrel on it. Everything after that is out of my control," Fielder said. "I try to put the barrel on it and see what happens."
The struggling Brewers have lost seven of nine and are 6-14 since starting 24-10, but snapped the Marlins' six-game road winning streak.
Florida's biggest move Thursday came off the field, when it agreed to send reliever Randy Messenger to the San Francisco Giants for struggling closer Armando Benitez, who saved 47 games for the team in 2004.
"We love Armando," assistant general manager Michael Hill said. "He did a great job for us in '04 establishing a single-season save record and brings experience, and we're happy to bring him back to the Marlins."
Fielder got to Marlins starter Wes Obermueller in the fourth for a two-run homer off the bottom of the batter's eye in center field to give the Brewers a 3-2 lead.
Fielder moved into a tie with the Yankees' Alex Rodriguez for the major league lead with 19 homers overall. He also set a franchise record for homers in any month, surpassing 12 set by Gorman Thomas (August 1979) and tied by Greg Vaughn (June 1996) and Jeromy Burnitz (June 1999).
"This team had a lot of great players. I'm just happy to be part of that," Fielder said. "Hopefully, I can keep playing strong and trying to help my team win."
Yost said he had only two relievers available the day after the Brewers' bullpen allowed eight runs in the final two innings of a 9-3 loss to Atlanta. Yost used both relievers, as Carlos Villanueva (4-0) threw two scoreless innings and Francisco Cordero earned his 19th save in as many chances.
The Marlins, on an 11-game, 10-day road trip, had started 3-0 and were looking to get back to .500 for the first time since May 4, but they squandered a bunch of opportunities, including a bases-loaded threat with one out in the fourth.
"You can't score every time," Marlins manager Fredi Gonzalez said. "In games like this, you can look back at every opportunity and really pick it apart."
Vargas went six innings, giving up three runs and six hits with two walks. He struck out six.
Obermueller, who pitched for the Brewers from 2003-05, looked much sharper than his previous start, when he gave up seven runs and eight hits in four innings against the Mets. He went seven innings against Milwaukee and allowed six hits and three runs.
"It felt real comfortable coming back," said Obermueller, who was the Brewers' opening-day starter in 2004. "I saw some of the same security guards and stuff, and a lot of my friends. I have a lot of respect for the organization for the opportunities that they gave me."
- Brewers 2B Rickie Weeks (right wrist) missed his second straight game and was placed on the disabled list retroactive to Wednesday. He will fly to Phoenix on Friday to talk to the doctor who performed his surgery last season. RHP Jose Capellan was called up from Triple-A Nashville to replace him.
- Florida 3B Miguel Cabrera drove in two runs.
- Third base umpire Eric Cooper wasn't on the field when the game started after "traffic issues" kept him from the ballpark. Cooper arrived and ran out to his position after three batters in the top of the first.
- Marlins RHP Josh Johnson (right elbow) will make a rehab start Sunday for Single-A Jupiter.
- Marlins 1B Mike Jacobs (broken right thumb) will not participate in baseball activities for the next three to five days.