CINCINNATI -- Coming off an All-Star campaign, Cincinnati Reds catcher Devin Mesoraco didn't expect to be relegated to a pinch-hitting role just two weeks into this season.

"It's certainly been difficult," said Mesoraco, who hasn't started behind the plate since April 11 due to a hip impingement. "I think I went about a month without getting hit. I wasn't healthy. I wasn't helping out."

On Tuesday night, Mesoraco's pinch-hit double off Atlanta Braves closer Jason Grilli drove home the winning run in the bottom of the ninth inning, helping the Reds to a 4-3 victory at Great American Ball Park.

It was the first walk-off hit of Mesoraco's five-year career.

"I haven't done it before," he said. "I've been in those situations where I wished I got a hit. To get this little opportunity and produce, it meant a lot."

Third baseman Todd Frazier homered for Cincinnati (16-17) for his sixth home run in his past 13 appearances. He's now tied with the Nationals' Bryce Harper for the National League lead.

With the score tied 3-3 in the ninth, Grilli (0-2) returned to the mound after missing three games with back spasms. He allowed a one-out single by catcher Brayan Pena, who was replaced by pinch-runner Michael Lorenzen.

Mesoraco laced a double into the left-field corner, and Lorenzen, a pitcher, scored the winning run from first.

"I'm just glad they pinch-ran for Pena," said Mesoraco. "I'm not sure he would've made it to third."

Pena went 3-for-4 with a pair of doubles to extend his hitting streak to five games.

"I was a little rusty maybe," Grilli said. "Other than that, I felt fine. I'm back in the saddle so we start from there."

The struggles continued for Reds starter Anthony DeSclafani, who allowed three earned runs and seven hits in six innings. He walked three and fanned five.

After not issuing more than two walks in any of his first four starts, DeSclafani has 12 free passes in his past three outings.

"He's been moving around the zone a little bit," said Reds manager Bryan Price. "His command in the zone of his fastball and changeup is not as good as we saw."

But, the Reds helped DeSclafani avoid his fourth straight loss when Pena singled leading off the seventh and later scored on left fielder Marlon Byrd's sacrifice fly, tying the score 3-3.

That run also denied right hander Mike Foltynewicz from becoming the first Braves pitcher since Ben Sheets in 2012 to win three consecutive starts to begin his Atlanta career.

He allowed three runs (two earned) on six hits in 6 2/3 innings. He struck out seven and issued a career-high four walks.

"Folty was outstanding," Braves manager Fredi Gonzalez said. "Every chance we get to get him in those situations, it's going to be good for him."

After Atlanta (15-18) stranded the go-ahead run at second base in the eighth, Reds closer Aroldis Chapman entered the game in a non-save situation for the third straight contest.

In the prior two outings, Chapman went 0-2 with two runs allowed. But he pitched a scoreless ninth on Tuesday to keep the score tied.

Chapman (2-2) earned the victory.

Frazier launched a 2-0 pitch from Foltynewicz into the left-field seats for a two-run home run, putting the Reds ahead 2-0 in the first inning.

Since allowing only three earned runs in four April starts, DeSclafani got roughed up on Tuesday night for the third straight outing.

Left fielder Kelly Johnson's RBI double and a sacrifice fly by third baseman Alberto Callaspo helped the Braves tie the score 2-2 in the third.

Atlanta grabbed a 3-2 lead in the fourth on right fielder Nick Markakis' two-out double, which drove home Jace Peterson. The second baseman went 2-for-3 with a double and walk.

NOTES: Several people were injured when a bus transporting the Braves' Class A affiliate Carolina Mudcats flipped over in Columbus County, N.C., at approximately 4 a.m. Tuesday morning. Eight players and a team trainer were treated and released from the hospital early Tuesday. "We dodged a bullet," said Braves manager Fredi Gonzalez. "That's something that could be really bad. Just some bumps and bruises." Tuesday's game in Myrtle Beach was postponed. ... Reds 2B Brandon Phillips left in the eighth inning with a toe injury. ... Reds SS Zack Cozart was out of the lineup for the second straight day with a sore left wrist. He pinch-hit in the seventh and reached on a fielder's choice. ... RHP Raisel Iglesias will make his second career start for Cincinnati on Wednesday.