He slid into second, just beating the throw, the historic hit arriving in a fashion that defined Helton's 17 years with the Rockies.
"A line-hugger that barely stayed fair on a 3-2 count," Helton said. "That's what's kept me in the league this long. That's my bread and butter, to go the other way, especially with two strikes. To do it on the 2,500th is very fitting."
The Coors Field crowd roared and rose to its feet, and Helton acknowledged his supporters with a wave and tip of his helmet.
Asked about what he would remember the next morning, Helton displayed his typical wit.
"I'll probably remember the umpire yelling, 'Safe,' because he could have very easily yelled, 'Out,'" Helton said. "So I was very appreciative."
Close friend and relief pitcher Matt Belisle gave him a hearty fist bump in the Rockies bullpen, his teammates welcoming him back to the dugout with words and congratulations. The crowd came to its feet once again at the end of the inning, appreciative not just of witnessing him join 95 other players with 2,500 hits, but of what he's done for this franchise in what is widely expected to be his final season.
"I'm just so happy and proud of my friend, just understanding the magnitude of what caliber player he is," Belisle said. "Even as we've been anticipating the 2,500th hit, it's sort of hitting home a little more right now. I think the standing ovation gave me a little goose bumps, so I can't imagine what it did for him and I'm thankful to the Denver fans for doing that."
Helton could breathe a sigh of relief, having reached the record in front of his home crowd. For a moment, the game paused, both dugouts taking a minute to absorb what they witnessed.
"I'm happy for him," Reds manager Dusty Baker said. "You'd be a hater if you weren't happy for the guy."
The win clinched the Rockies' third straight series victory, the first time they've done that since July 20.
With the game knotted at 2, the Rockies surpassed their run total in Saturday's loss with four runs in the fifth. Pinch-hitter Jordan Pacheco and Corey Dickerson jump-started the offensive outburst with two infield singles, and DJ LeMahieu drove both home with a double to right-center.
Cuddyer ripped a double to left to give the Rockies a 5-2 lead, enough for Baker to pull the plug on starter Mike Leake. Nolan Arenado lifted a sacrifice fly to left for Colorado's final run.
Leake departed after 4 1/3 innings, allowing eight hits and six runs, striking out four and walking two.
Opposite the Reds starter, Tyler Chatwood made his first start since July 31, Colorado's rotation finally nearing full strength. But Chatwood's first start for the Rockies in more than a month ended before it ever really began.
Chatwood took a line drive off the bat of Leake (11-6) in the third inning and exited soon after with a bruised left thumb, allowing four hits and two runs in two-plus innings of work. His hand swelled and Chatwood said he had no feeling in his thumb, but X-rays were negative.
Chatwood's day ended after he walked the next two batters, with the Rockies' staff pulling him on its second visit to the mound. He tried to fight through the inning, but manager Walt Weiss knew he needed to get Chatwood out of the game.
"It was frustrating," Chatwood said. "You wait a month to start, and that happens."
Cuddyer's first RBI double came in the first inning, driving in Dickerson, who reached second on a ball that dropped between three Reds players who appeared to lose the ball in the sun. Arenado tacked on another run in the second when he sent his 10th homer into the left-field seats. "Watching Cuddy in front of me, there's your inspiration," Helton said. "He had some fabulous swings tonight. Arenado on defense. I'm pleased and happy I got it in a winning effort."
Stellar defense and smart pitching from reliever Adam Ottavino kept Cincinnati from grabbing the lead. After a nice play to get to a ground ball, Troy Tulowitzki's throw wasn't enough to beat a springing Chris Heisey at first. But Helton, a three-time National League Gold Glove Award winner, spun around and made a perfect throw home that caught Joey Votto a few steps ahead of home plate to end the inning.
Ottavino shined after Chatwood's early exit, allowing just three hits over three scoreless innings.
"The fact that we lose our starter in the [third] inning, at that point you're just hoping you don't blow up the bullpen, you get through the game," Weiss said. "But to win that game, Ottavino to come in and do what he did was huge." Cuddyer completed his 4-for-4 day with a solo homer in the seventh, his first since July 28.
But Helton's one at-bat consumed the game. And there may have been no better man to offer perspective on Helton's career than Weiss, a teammate of Helton's when he made his Major League debut on Aug. 2, 1997.
"I remember when he first showed up," Weiss said. "He showed up with a lot of hype and he lived up to that hype, every bit of it and then some. It's been an amazing career."