"The biggest key was just minimizing the damage," Mesoraco said. "Those guys, they battle until the end. We put up a big lead, and they never give up. They always come back on us. It was definitely a battle, but guys did their job, and we got through it."
Chapman was summoned for the final three outs but found the ninth to be treacherous from the get-go.
Andrew McCutchen led off with a sharp grounder to third base that backed up Jack Hannahan, who double-pumped before his late throw to first base, giving McCutchen his fourth hit. An errant pickoff attempt by Chapman then moved McCutchen to second base before a Pedro Alvarez grounder to shortstop was muffed by Zack Cozart. It was his second error of the day -- the team's third overall -- and put the potential tying run on third base with no outs.
"That's uncharacteristic of our team, especially Cozart. He doesn't make any [errors]," Reds manager Dusty Baker said.
From that point, Chapman simply took over the game. Not a single pitch to his final three batters was below 100 mph.
"He wasn't depending on defense. He wasn't depending on anybody other than himself," Baker said. "We were just hoping we didn't have a passed ball or something like that to tie the game. It was a game that we needed."
On the third fastball to Russell Martin, Chapman got a routine pop fly to second base for the first out. Pinch-hitter Michael McKenry fouled off three of the first four fastballs he saw before swinging through a 101-mph pitch for strike three.
Jordy Mercer became the final batter when he was retired on three pitches, capped by the 102-mph pitch that secured Chapman's 23rd save.
"That was an awesome situation," Mesoraco said. "It was really cool to see Chapman just really keep his cool and go out there and just go after the guys. In that situation, with a runner on third and less than one out, you need to either strike them out or induce soft contact. I'm not thinking about double play. I'm trying to get out of it the easiest that we can.
"There we threw maybe 20 straight fastballs in just to induce weak contact or have them swing through it. He was pumped up. That was definitely a fun thing to see."
And thus ended a nearly five-hour slog of a late afternoon -- with a one-hour, 17-minute rain delay mixed in when storms rolled through following the top of the first inning.
"You're trying to square up one of the best closers in the game with the velocity and the angle," Pirates manager Clint Hurdle said. "And we got ourselves in as good of a position as you could want at first and third with no outs. We weren't able to get the run in then; we had multiple opportunities before then."
When play resumed following the delay, the Reds jumped Pirates starter A.J. Burnett for four runs and sent nine to the plate. Being idle for nearly 90 minutes from the rain delay and a long rally did Reds starter Mat Latos no favors. Baker did not consider starting the game with a reliever instead as the storms approached to save Latos for after the delay.
"I've seen it where they made everybody delay and it didn't rain for three hours and the sun came out," Baker said.
Latos threw two simulated innings in the club's indoor batting cage to stay warm.
"If we had gone a whole lot longer, he might not have been able to come back," Baker said. "As it was, he was at 100 pitches in the fifth. He was really at about 125-130, including what we threw underneath to stay warm."
Latos wasn't sharp, but his line appeared better than his afternoon seemed -- allowing three runs (two earned) and four hits over five innings, with four walks and five strikeouts.
"It's not something I've had to do," Latos said. "There's a first time for everything."
Pittsburgh's second inning began with a leadoff homer by Garrett Jones. A two-out error by Cozart on a fielder's-choice grounder by Jose Tabata scored another run as Latos needed 29 pitches to get through the inning. McCutchen's two-out solo homer to left-center field in the fourth pulled the Pirates to within one run. It was the second day in a row that the Reds had to hang on tight after taking a big lead.
"The whole bullpen picked me up today, and the offense, with the four early runs off a good pitcher," Latos said.
Reliever Sam LeCure caught a break in the seventh. McCutchen smoked a ball to the wall in right field and was on his way to an easy triple until he fell down between second and third base. He was tagged out in a rundown to squelch a potential opportunity.
In the eighth, the Pirates loaded the bases against Reds reliever Alfredo Simon, prompting Baker to call on Logan Ondrusek to put out the fire. Ondrusek got Tabata to ground out.
"It's just a huge deal for us to try and go out and execute the best we can. We had a plan, went after him and attacked him," Ondrusek said. "I tried to get him to chase a little bit. He laid off a couple, which made it a little closer. I made the pitch when I needed to and got the huge ground ball."
The third-place Reds, who have taken the first two games of the three-game series, closed to two games behind the second-place Pirates in the National League Central race.