PITTSBURGH -- At 5-foot-7, Josh Harrison knows better than to try playing the big man's game.
Thus, the utility man was as surprised as anyone in PNC Park when led off the bottom of the ninth inning with a pinch-hit home run to rally the Pittsburgh Pirates to a 4-3 victory over the Miami Marlins on Tuesday night at PNC Park in the opener of a three-game series.
"I wasn't going up there thinking 'Let's hit a walk-off home run,'" Harrison said. "I was thinking, 'Just try to get on and get the game-winning run.'"
It was the second home run of the season and first career pinch-hit homer for Harrison, who was batting for Garrett Jones.
Harrison sent a 1-1 pitch from Mike Dunn (2-3) over the wall in right-center. That touched off a wild celebration for the National League Central-leading Pirates, who improved their record to 68-44, best in the major leagues.
"It felt amazing," Harrison said. "I'd like to think (my feet touched the ground), but I don't know. I was running pretty fast when I hit it. It was a great feeling."
With the scored tied 3-3 In the eighth, the Pirates loaded the bases against Chad Qualls with none out. Dunn, a left-hander, relieved and struck out Pedro Alvarez looking before Russell Martin grounded into a double play with shortstop Adeiny Hechavarria making a nice play on a bad short hop.
However, Dunn's magic ran out three pitches into the ninth inning when he tried to go inside on the right-handed-hitting Harrison and left a ball belt-high on the outside corner of the plate.
"I made a mistake, and he did a good job of driving it the other way," Dunn said.
Marlins manager Mike Redmond had right-hander Ryan Webb warming up but opted to with Dunn as the Pirates had left-handed-hitting Alex Presley on deck.
"I thought he'd be all right to get the pinch hitter there, and with the lefty on deck, get us through the inning," Redmond said. "At least, it forced them to make a move, and you tip your hat to the guy because he got a big hit.
"It's tough for Dunner. He did a great job in the eighth. It's a tough deal for him, man, to have to lose that game."
Neil Walker had three hits for the Pirates, and Andrew McCutchen had two hits and two RBIs for his fourth consecutive multi-hit game.
Bryan Morris (5-4) pitched a scoreless ninth for the win as the National League Central-leading Pirates improved to 7-2 on their season-long 11-game homestand.
The Marlins' Donovan Solano had three hits, and Ed Lucas and Logan Morrison added two hits apiece.
Neither starter figured in the decision.
Jeff Locke lasted 5 2/3 innings for Pittsburgh, giving up three runs and nine hits while walking three and striking out four. Locke pitched a season-low four innings in his previous start, and manager Clint Hurdle expressed some mild disappointment in the All-Star left-hander.
"There are lessons to be learned for him," Hurdle said. "He's always got to be the predator and the aggressor. We're into August, we're into September. Everybody that gets that ball, you've got to be throwing aggressive punches off the mound with intent and conviction."
Miami's Henderson Alvarez went seven innings and allowed three runs and six hits with no walks and six strikeouts. Marlins starters have allowed three or fewer runs in 39 of their past 44 games.
The Marlins (43-68) stranded 11 baserunners.
"We've been playing that same game all year, I don't know how many times," Redmond said. "We couldn't get that hit to give us a little breathing room."
The Pirates tied the game at 3-3 with a three-run third inning. McCutchen hit a two-run double off the center field fence with two outs, and Pedro Alvarez followed with a triple to right-center.
The Marlins built a 3-0 lead on Henderson Alvarez's sacrifice fly in the second inning and four consecutive singles to lead off the third by Lucas, Giancarlo Stanton, Morrison and Solano, with the last two driving in runs.
However, it wasn't enough to prevent the Pirates from notching their 26th comeback win of the season.
"I've never been around a group of guys that fights this hard the entire game," Locke said. "We don't score any runs for five innings, and you see who comes up with nobody on and walks off. It's a funny game."
NOTES: The series continues Wednesday night with Miami RHP Tom Koehler (3-6, 4.34) pitching against Pittsburgh RHP Charlie Morton (3-3, 4.07). ... Pirates OF Travis Snider, who has been on the disabled list since July 28 with left big toe discomfort, began playing catch Tuesday and hopes to start jogging by the end of the week. ... Pittsburgh OF Starling Marte's eight-game hitting streak ended as he went 0-for-3. ... Before Tuesday night's game, Miami RHP Jose Fernandez downplayed winning the NL Rookie of the Month award for July on Monday. "It's a great honor but, as a pitcher, you only win games with the help of your teammates," he said. "You need run support, and you need the guys to play good defense behind you."