Thanks to a second consecutive blown lead by the bullpen, however, the Reds needed Joey Votto's first career walk-off home run to make sure Volquez's efforts weren't wasted. Votto led off the 10th inning by smacking reliever Justin Thomas' 2-1 pitch into the left-field seats for his 33rd jack of the season.
The Reds' 81st win ensured their first non-losing season since 2000. More importantly, it increased the club's lead over St. Louis to seven games in the National League Central after the Cardinals lost, 6-3, in 12 innings vs. the Braves.
If the Volquez of Saturday night continues the rest of the season, the Reds will be all the more likely to be playing in the postseason for the first time since 1995. The magic number for the Reds to clinch the division title is now 15.
"The magic number is one for that day," said Reds manager Dusty Baker. "But if [Volquez] does that, his return to form makes him, if not your best, one of the best. That was an outstanding performance. I wish he had gotten the win, but I'm more excited about how he pitched and how he might pitch down the stretch."
The Reds led, 3-0, when Volquez was lifted for a pinch-hitter in the seventh. They were able to score a pair of runs off Pirates starter Charlie Morton and reliever Chris Resop in the seventh to give them a seemingly comfortable cushion.
Nick Masset struck out Ryan Doumit to open the eighth inning, but the Pirates responded with four runs on four hits. Masset was charged with all four runs, although it was Neil Walker's two-out, two-run single off phenom Aroldis Chapman that put Pittsburgh into the lead.
"Volquez was as nasty as we've ever seen him," Walker said. "We knew once we got Volquez out of the game we could give ourselves a shot. We did a lot of nice things tonight, but you have to tip your cap to them. They're in first place for a reason."
Jose Tabata had the lone hit off Volquez, a grounder up the middle in the first inning that glanced off Orlando Cabrera's glove and into center field. Volquez walked Garrett Jones with two outs, but he was the last to reach base off Volquez.
Trailing by a run in the ninth inning, Chris Heisey doubled down the third-base line with one out off Pirates closer Joel Hanrahan to plate Drew Stubbs from first base and tie the score at 4. Heisey wasn't expected to play after straining his left biceps muscle on Friday, but he replaced Miguel Cairo for defensive purposes in the eighth.
"[Dusty] knew I'd be able to play, but he was trying to take precautions," Heisey said. "At that point, it didn't even look like I was going to get an at-bat. It was a wild game. Sometimes you can't script it. And then they weren't sure if they were going to pinch-hit for me because he was trying to keep me away from swinging tonight. I guess he went with his gut and it worked out for us. I'm obviously glad he stuck with me."
Francisco Cordero (6-4) earned the win by pitching a perfect 10th inning. Cordero who gave up a pair of runs in the ninth inning on Friday to blow a 3-1 lead after Homer Bailey had put the Reds into position to win in regulation. They eventually won, 4-3, in 12 innings.
Votto didn't let the drama go on that long Saturday. The crowd rose to its collective feet with anticipation of the MVP candidate doing something special -- and he delivered.
"That was really cool," Votto said. "I'm glad it came after losing the lead and then coming back in the bottom of the ninth. I think it showed that it was my occasion to help us win, but every other day it's someone different. Today, I guess, it was my turn.