"It was definitely a rough inning for me," Fiers said. "I wasn't helping myself walking guys. ... They hit my mistakes, I walked guys. It was a bad inning."
After Fiers retired Carlos Lee to lead off the frame, seven straight Marlins reached base. Justin Ruggiano and Rob Brantly singled to put two aboard for Donnie Murphy, who singled to right to tie the game at 2.
Miami took the lead when starter Ricky Nolasco attempted a squeeze bunt with runners on the corners. Fiers tried to glove flip the ball to Jonathan Lucroy at home, but Fiers missed the ball -- his second error of the afternoon.
"Luckily that in-between bounce, I guess, it was a tough play for him," Nolasco said. "I tried to get it down to give Brantly enough time to score. We just caught a break."
Added Fiers: "I thought I had a chance at [Brantly at the plate] so that's why I went for it. It just went over my glove. I don't know how, it was weird, but I should've made that play and it cost me another run."
Fiers' first error came an inning earlier when an errant pickoff attempt led to the Marlins' first run.
"Those were big plays that I need to make and I didn't make them," Fiers said.
Milwaukee manager Ron Roenicke thought the two misplays may have gotten into Fiers' head, with the second error -- which led to three Miami runs -- possibly affecting the pitches the right-hander made the rest of the way.
"I think if those two plays don't happen, it's still a close game, and I think he still mentally is feeling good and I think it could be different," Roenicke said.
After the squeeze play, Fiers walked Gorkys Hernandez and then gave up back-to-back RBI singles to Donovan Solano and Jose Reyes, the latter driving in two runs and bringing an abrupt end to Fiers' outing. He lasted 3 1/3 innings and gave up six runs, four earned, on six hits and four walks while playing in front of more than 45 friends and family members.
"It was great that everyone came, I just wish I would've done a little bit better for my team and for my friends and family that came," Fiers said. "It didn't work out that way."
Livan Hernandez relieved Fiers and pitched 2 2/3 perfect innings of relief. Brandon Kintzler, who was called up before the game, followed with a hitless inning of his own in his first appearance since May 4, 2011.
The disastrous fourth inning erased an early two-run lead that Milwaukee built in the second courtesy of Carlos Gomez, who belted his 16th homer of the season and the Brewers' National League-leading 168th of the year.
Lucroy had reached on an error when he hit a sharp grounder that went between Murphy's legs at third. Two pitches later, Gomez launched a two-run shot off Nolasco that bounced off the top of the left-field wall and into the Marlins bullpen.
"It was a good [bounce]," Gomez joked.
Gomez's wall-scraper was one of the only friendly bounces for the Brewers at Marlins Park. Jean Segura committed an error in the seventh, and then Rickie Weeks committed Milwaukee's fourth of the day in the eighth, leading to an insurance run for the Marlins. It was the first time the Brewers committed four errors in a game since May 18 against the Twins.
"[It was] a little tough," Roenicke said. "Overall a couple mistakes, but we've been playing good defensively."
After Gomez's home run, the Brewers were unable to get anything going against Nolasco until the seventh. Ryan Braun drove in Segura after a Reyes error gave Milwaukee an extra out. Two of Milwaukee's three runs Monday were unearned.
With two men on, Aramis Ramirez came to the plate as the tying run but Nolasco got him to bounce into a fielder's choice and end the scoring threat as the Brewers stranded nine on the afternoon, including two more in the ninth.
"I thought [Nolasco] was tough," Roenicke said. "We had some opportunities that we could've scored but he did a nice job of keeping the ball down."