Miami erased a four-run deficit to claim its 15th comeback victory, along with snapping a two-game slide. It also ended the club's six-game slide at Busch Stadium dating back to 2012.
After hitting into a game-ending double play with the bases loaded in Friday's 3-2 loss, McGehee said he wished he had that at-bat over again. He got his chance. With two outs and Donovan Solano on first, McGehee had an 11-pitch showdown with Trevor Rosenthal. This time, the result went McGehee's way.
"As frustrating as sometimes it might be, I try not to bring last night back to the field with me," McGehee said. "Sometimes it's a little easier said than done.
"It's hard enough to go up there and hit big league pitching. If you're doing it with a vendetta or revenge or whatever and frustration in your mind, it makes it even that much harder."
McGehee singled to the gap in right-center, and Solano scored from first. Baker followed by putting the Marlins in front with a single to left off lefty Sam Freeman.
Rallying from four runs down to win matched a team high deficit overcome by the Marlins, who previously did it in a 7-6 win over the Mets on April 26.
McGehee has been playing at an All-Star level all season, and the Marlins are pushing hard for the 31-year-old to be selected to the National League squad, which will be announced on Sunday.
"That's an All-Star at-bat for Casey McGehee right there," Miami manager Mike Redmond said. "Last night he had a chance and it didn't work out, and today it did. He's been like that all year. It's been a true pleasure to watch him compete. Today he got a big hit, followed by Bake's big hit."
The National League manager will be St. Louis' Mike Matheny, who gave credit to the Marlins' third baseman.
"Great at-bat, no question," Matheny said. "He's putting together a great season."
McGehee fouled off five straight pitches with the count full before finding the gap with the tying hit.
"Obviously a great AB by Casey," Marlins left fielder Christian Yelich said. "Probably one of the best ones we've had all year. Then the Bake Show comes and he gets that hit."
Yelich pulled Miami to within one run with a three-run homer in the sixth inning. The 22-year-old endorsed McGehee for the All-Star Game.
"Look at today, that's all I have to say," Yelich said. "Look at that at-bat in the ninth inning. That's pretty impressive. ... He's been doing that all year. That's a night after night thing that he goes out and does. I think he is definitely deserving."
The Marlins' rally got Andrew Heaney off the hook for his fourth straight loss. In 3 2/3 innings, the 23-year-old gave up five runs on eight hits with three walks, a hit batter and one strikeout. He was optioned to Triple-A New Orleans after the game.
Allen Craig and Jhonny Peralta belted back-to-back homers off Heaney in a four-run fourth.
In four big league starts, Heaney has now been tagged for five home runs in 20 2/3 innings. Before being called up from New Orleans, the lefty had given up three homers in 76 2/3 innings.
"You can't fall behind 2-0 on every guy and expect to get good results," Heaney said. "I've just got to make better pitches than that. I didn't attack the strike zone. I didn't establish anything, so the second, third time around, they know I'm having to groove some pitches in there. That didn't work."
McGehee stayed hot with an RBI single in the first inning off Miller, who gave up three runs in 5 1/3 innings. The third baseman has now hit safely in 12 straight games, a career high. He also has a streak of collecting a hit in 19 consecutive road games, and he has reached base safely in 28 straight games overall.
The question will be answered Sunday if he is All-Star worthy.
"I'd be lying if I said I don't care," McGehee said. "But at the same time, it's not going to make or break my year, or my day, being on it or off it. It would be a tremendous honor to be selected. As long as the 24 other guys and the coaches in this clubhouse has faith in me to do my job and trust me to do my job, that's all I can ask for. Anything else is just kind of extra. It would be curious to find out, for sure. By no means am I expecting or am I going to have my feelings hurt if it doesn't go that way."