The Pirates are on the verge of hosting the NL wild card game for the third straight year.
The Pirates (97-63) maintained a two-game lead over the Chicago Cubs for home-field advantage Wednesday night in the NL wild-card game. Pittsburgh can ensure the game is at PNC Park with a win in either of its two remaining games or one Cubs loss in Milwaukee.
"It's exciting, especially in this game where we're trying to play at home," Marte said after the Pirates rallied from a 4-0 deficit. "We play good baseball at home. We want to make our fans happy. We want to play here."
Andrew McCutchen had three hits for the Pirates, including a home run.
Gregory Polanco drew a one-out walk from Colin Balester (1-1) in the 12th. Marte hit the next pitch into the right-field stands for his 19th homer this season and his third career walkoff shot. He also hit a game-ending homer Aug. 22 against San Francisco.
"He continues to show up big," Pittsburgh manager Clint Hurdle said. "He likes the big situations."
Arquimedes Caminero (5-1) pitched a scoreless inning for the win.
Eugenio Suarez had two hits and three RBIs, including a two-run homer, for the Reds.
Both starting pitchers lasted five innings.
Pirates left-hander Francisco Liriano allowed four runs and seven hits, and his five strikeouts raised his season total to a carreer-best 205, four more than his he had in 2010 with Minnesota.
Reds rookie Keyvius Sampson gave up four runs and three hits while striking out seven and walking two. The 24-year-old is 0-5 in his last nine starts.
Pittsburgh tied it 4-all with a three-run sixth inning after loading the bases with none out to chase Sampson.
Cincinnati took a 4-0 lead with a pair of runs in both the second and third.
Suarez hit his 13th homer of the season in the second. An inning later, Jay Bruce hit an RBI double and Suarez followed with a run-scoring single.
McCutchen pulled the Pirates to 4-1 when he led the fourth inning with his 23rd homer.
"I'm kind of at a loss for words right now," Cincinnati manager Bryan Price said. "Hard-played game, had to exploit most of the bullpen, a lot of guys down there on fumes and just trying to find a way to get through it and put ourselves in a position to win a game."
Joey Votto tied a Reds record by reaching base safely in his 48th consecutive game. Votto singled in the third inning off Liriano to match Pete Rose's mark set in 1978.
Rose's run included a 44-game hitting streak, the longest in NL history.
Votto also reached base for the 316th time this season, equaling the club record he set in 2013.
Reds: LHP Brandon Finnegan (4-2, 3.86 ERA) will make his fourth start for Cincinnati. He is 1-2 with a 6.00 ERA since moving into the rotation Sept. 18.
Pirates: RHP A.J. Burnett (9-6, 3.15) is 1-1 with a 3.68 ERA in four starts since being on the disabled list from July 31 to Sept. 9 with a strained flexor tendon in his right elbow. Burnett plans to retire at the end of this season, so this would likely be the last game of his 17-year career if the Pirates lose the wild-card game.
Copyright 2015 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.