PITTSBURGH -- The long baseball season gives just about everyone the opportunity to be a hero, even someone like Pedro Florimon, a utility infielder who is the 25th player on the Pittsburgh Pirates' 25-man roster.

Florimon's triple in the bottom of the 15th inning gave the Pirates a 9-8 victory over the Arizona Diamondbacks on Tuesday night after they blew a late five-run lead.

Catcher Francisco Cervelli hit a two-out single off rookie left-handed reliever Keith Hessler (0-1) for his fourth hit of the game and Florimon, who entered the game in the ninth inning at shortstop as a defensive replacement, followed with a drive off the right-field wall.

Florimon has spent the majority of the season at Triple-A Indianapolis and has gone just 2-for-19 (.105) in 16 games with the Pirates.

"To come up and get a hit like that, it's gratifying to see," Pirates manager Clint Hurdle said. "It's gratifying for him, too, for the all the work to put in down at Indianapolis to get back up here."

Florimon said it was the first walk-off hit of his 10-year professional career at any level.

"It was exciting," Florimon said with a smile. "I just always try to stay ready for whenever they need me and it feels good to help the team win the game."

The National League wild card-leading Pirates (70-47) won for the fifth time in six games.

Hessler was in his second inning of work. He singled in the top of the 15th for his first major league hit but throwing out trying to stretch it into a double.

"Everything was going good and then a couple mis-located pitches," Hessler said. "That's what happens. Unfortunately it went just far enough and off the wall where he was able to score from first on it. Two outs, you know he's running on contact. Very frustrating but it's just the way it worked out."

The Pirates led 8-3 after seven innings but the Diamondbacks (58-60) scored three times in the eighth inning then two unearned runs off closer Mark Melancon on a pair of errors in the ninth to force extra innings.

The Diamondbacks, who lost for the fourth time in six games, tied it at 8-8 when first baseman Sean Rodriguez let first baseman Paul Goldschmidt's grounder roll between his legs for a three-base error. Rodriguez entered the game an inning earlier as a defensive replacement for Pedro Alvarez.

Pinch hitter Ender Inciarte reached first to lead off the inning when third baseman Jung Ho Kang booted his ground ball. Third baseman Aaron Hill kept the rally alive with a two-out single.

It was just the second blown save of the season for Melancon, who leads the major leagues with 37 saves.

Hill had three hits for the Diamondbacks, who are averaging 5.24 runs in 17 games in July, and center fielder A.J. Pollock added two.

The Diamondbacks got within 8-6 in the eighth when Goldschmidt drew a bases-loaded walk from right-handed reliever Jared Hughes, catcher Welington Castillo hit a sacrifice fly and right fielder Yasmany Tomas had an RBI single.

Kang and left fielder Starling Marte both homered and also had two hits along with Alvarez, right fielder Gregory Polanco and center fielder Andrew McCutchen.

Right-handed reliever Joe Blanton (3-0) pitched three scoreless relief innings for the win.

Kang's homer was a solo shot in the seventh inning, his 10th of the season, off Josh Collmenter that seemed to put the Pirates safely ahead at 8-3.

"You just keep playing," Hurdle said of squandering the lead. "Our guys are good at that."

Diamondbacks starter Chase Anderson was tagged for seven runs -- five earned -- and nine hits in 4 2/3 innings with five strikeouts and two walks. The right-hander has a 7.59 ERA in his last eight starts after posting a 2.84 mark through his first 13 starts of the season.

In seven-plus innings, Liriano allowed five runs and six hits with three walks and five strikeouts. Liriano remained unbeaten in nine starts since his last loss June 20 at Washington, though his team's ninth-inning meltdown cost him what would have been his fifth win in that stretch.

It was the longest game by innings for the Pirates since they played 16 innings against the Diamondbacks at PNC Park on Aug. 18, 2013. Arizona played a 17-inning game May 31 at Milwaukee.

Marte's 14th home run of the season, leading off the third inning, put the Pirates ahead 4-3.

The Pirates extended the lead to 7-3 with a three-run fifth. Alvarez hit a two-run single with two outs to chase Anderson, and Cervelli greeted reliever Josh Collmenter with an RBI single.

NOTES: Diamondbacks OF Ender Inciarte, who has started at all three outfield spots in the past week, was rested as Arizona started an outfield of LF David Peralta, CF A.J. Pollock and RF Yasmany Tomas. ... Pirates manager Clint Hurdle said he feels pitch location, rather than fatigue, is the primary reason RHP Gerrit Cole has gone 0-3 with a 4.70 ERA in four August starts after entering the month with a major league-league 14 wins. ... The three-game series concludes on Wednesday night with Arizona LHP Robbie Ray (3-8, 3.29 ERA) facing Pittsburgh LHP J.A. Happ (0-1, 4.66 ERA).