Pirates closer Jason Grilli had been perfect on 25 save chances, the Pirates had not lost a lead after eight innings, and Pittsburgh led 1-0 in the ninth.
But Jay Bruce, whose homer Monday was the last run the Reds had seen, ended the drought with a tying homer, and Brandon Phillips' single up the middle with the bases loaded in the 13th drove home Derrick Robinson with the winning run in the Reds' 2-1 victory.
The Reds (44-29) remained 2 1/2 games behind the first-place St. Louis Cardinals in the NL Central standings. The third-place Pirates (42-30) dropped four games back.
The Pirates led 1-0 with one out in the ninth when Bruce hit Grilli's first pitch 417 feet to right field, tying the score 1-1.
"I've had pretty good success against him," Grilli said. "You feel horrible because the bullpen has been working a lot and we had to go extras and work harder. You lose a tough ballgame in an important series."
It was Grilli's first blown save this season after 25 straight conversions and the Pirates' first loss when leading after eight innings.
"You never plan on losing, but those things are going to happen occasionally," Pirates manager Clint Hurdle said. "That's the first time he hasn't been able to close, and it's June 19? That's pretty good."
In the 13th, Robinson reached on an infield single against Pirates right-hander Vin Mazzaro and advanced to third on Shin-Soo Choo's single. Joey Votto was intentionally walked to load the bases. Phillips' grounder up the middle snuck into center field for the game-winner.
"I haven't been myself lately," Phillips said. "It felt good to come through for the team. I'm trying to get back to my same approach and let the game come to me. I was glad to get that chance tonight."
Reds manager Dusty Baker said, "It's about time we won one of these games. These games take a lot out of you when you win, too."
NEXT: Pirates (Brandon Cumpton, 0-0, 5.40) at Reds (Homer Bailey, 4-5, 3.80)
2B Brandon Phillips was hitting .176 in 12 games since missing four after being hit on the left forearm by a pitch from Pirates LHP Tony Watson. "He's just trying too hard," manager Dusty Baker said prior to Wednesday's game. "He's not hurting. He's swinging at bad pitches." Phillips now ranks second in the National League with 57 RBI, including a bases-loaded RBI single in the 13th inning Wednesday that lifted the Reds to a 2-1 win. "I'm trying to get back to my same approach," Phillips said.
OF Chris Heisey postponed his second rehab appearance for Triple-A Louisville at Durham, N.C., on Tuesday due to wet conditions. Heisey, on the disabled list since April 29 with strained right hamstring, played for the Bats on Wednesday night and went 2-for-3 with a walk.
RF Jay Bruce has a flair for the dramatic. His solo homer in the ninth inning Wednesday was his third career game-tying homer in the ninth, and it came off Pirates closer Jason Grilli, who to that point was 25-for-25 on save opportunities this season. Bruce also has five career walk-off homers, including one that helped the Reds clinch the National League Central title in 2010. He leads all right fielders in RBI, doubles and hits.
RHP Jonathan Broxton has been shut down since being placed on the DL on June 15 with a flexor mass strain in his elbow. Broxton has been limited to strengthening exercises but could begin a throwing program this weekend. He has struggled at times in his role as the Reds' primary setup man, going 2-2 with a 4.33 ERA in 29 appearances.
LHP Sean Marshall is still at least two weeks away from coming off the disabled list, but he is progressing well. Marshall's long toss is up to 120 feet and he's throwing without discomfort. The Reds miss Marshall's presence as a left-handed specialist in the bullpen. In 11 appearances sandwiched around two stints on the DL, Marshall has gone 0-1 with a 2.57 ERA.
RHP Homer Bailey has fared well in his career against the Pirates, including a no-hitter at PNC Park on Sept. 28, 2012. In 12 career starts against the Bucs, Bailey has gone 8-2 with a 2.51 ERA. Twice in his past six starts Bailey has been the victim of blown saves. Aside from two starts in which he allowed seven earned runs, Bailey's season ERA is 2.66.
"It's about time we won one of these games. These games take a lot out of you when you win, too."—Manager Dusty Baker, after the Reds beat the Pirates in 13 innings Wednesday.
RHP Jonathan Broxton (flexor mass strain in right elbow) went on the 15-day disabled list retroactive to June 14. He could begin throwing the weekend of June 22-23.
OF Chris Heisey (strained right hamstring) went on the 15-day disabled list retroactive to April 28. He began a rehab assignment with Triple-A Louisville on June 17.
LHP Sean Marshall (sprained left shoulder) went on the 15-day disabled list retroactive to May 21. Marshall was on the DL due to left shoulder tendinitis April 10-26.
RHP Nick Masset (right shoulder surgery in September 2012) went on the 15-day disabled list retroactive to March 22, and he was transferred to the 60-day DL on April 21.
LF Ryan Ludwick (torn labrum in right shoulder) went on the 15-day disabled list retroactive to April 1, and he was transferred to the 60-day DL on April 15. Ludwick had surgery April 3. He might not return before July.
RHP Mat Latos
RHP Bronson Arroyo
RHP Homer Bailey
RHP Johnny Cueto
RHP Mike Leake
LHP Aroldis Chapman (closer)
LHP Manny Parra
RHP Sam LeCure
RHP J.J. Hoover
RHP Alfredo Simon
RHP Curtis Partch
LHP Tony Cingrani
1B Joey Votto
2B Brandon Phillips
SS Zack Cozart
3B Todd Frazier
INF Jack Hannahan
INF Cesar Izturis
LF Derrick Robinson
CF Shin-Soo Choo
RF Jay Bruce
OF Xavier Paul
OF Donald Lutz