On the second pitch of the at-bat, both runners advanced on a wild pitch. With a 2-2 count, McGehee sent a 93 mph sinker from right-hander Jared Hughes to right for the game-winning sac fly.
"The more times you're in big spots, the easier it is to slow yourself down and not get overexcited and still have a clear head," McGehee said. "I think that helps. I think that's part of maturing as a player, too. Every time those situations come up -- not that it gets easier -- but you keep your head about you a little bit."
Before that chance even arose, it was McGehee's defensive play that kept the score tied at 2.
A struggling A.J. Ramos loaded the bases with no outs. After falling behind 3-1 to Russell Martin, he induced a 5-2-3 double play started by McGehee's quick throw to home. Ramos ended the threat by striking out Clint Barmes.
"I had to earn that one," Ramos said. "I had to work for that one. It's a good feeling. I'm just glad we pulled it out. This team is amazing."
Exiled to Japan after a pair of subpar big-league seasons, McGehee dominated with 28 homers and 93 RBI last year with the Tohoku Rakuten Golden Eagles.
This past offseason, there was little fanfare when the Marlins signed the 31-year-old as a stopgap for top draft pick Colin Moran.
"I think we all talked about him as a player," manager Mike Redmond said. "I remember playing against him in Milwaukee and I knew he could hit. Going to Japan he was able to get that swing going. I think we all envisioned this. Did we think (that would happen)? We didn't know.
"We all hoped that this was the guy we were signing and sure enough he's made the most of this opportunity. I'm really glad he's on our team."
His performance Sunday -- going 3 for 4 -- extended his hitting streak to 10 games, one shy of his career high set in 2011. His 30 hits with runners in scoring position pace the majors. During a 100-loss season in 2013, Adeiny Hechavarria led the club with 29 all year.
Through 67 games, McGehee leads National League third basemen in average (.309) and RBI (46) and has committed just three errors. McGehee perfectly represents this Marlins club -- an early-season surprise.
Surely this success feels great for McGehee, who seems to have regained his 2010 form when he hit .285 with 23 homers and 104 RBI behind slugger Prince Fielder with the Brewers.
"I've seen how quick it can change, how quick things can go south if you start patting yourself on the back," McGehee said. "Hopefully end of the year I can look up and evaluate how I did. Just keep my head down and do my job."