With the win, the D-backs earned a split of the four-game series and ended their 10-game road trip, which also included series with the Dodgers and Phillies, with a 6-4 record.
The D-backs swept the Dodgers to start the trip, and took the first game of the series with the Phillies before dropping the final two and then splitting with the Pirates. Arizona was 4 1/2 games in back of the Giants in the National League West when the club left, and will return four out.
"It started great and ended on a good note," Kubel said. "We let a couple of games slip by us, but at 6-4, we really can't complain. We're moving in the right direction."
Kubel, who had been in a slump, was out of the starting lineup on Wednesday, though he did have to come in late in the game when outfielders Chris Young and Justin Upton were ejected.
A pair of off-days seemed in the offing, but Gibson had a change of heart Thursday morning.
"It was a good thing," Kubel said of Gibson's reversal. "I'll definitely take this over an off-day."
Kubel made his presence felt early on Thursday with a two-run homer in the first.
The Pirates grabbed the lead in the second, as they scored three times to go up, 3-2. They made Saunders work hard during the inning, as he threw 30 pitches.
"The second inning was not much fun," Saunders said. "I was making pretty good pitches. They were still finding holes. I just kept telling myself, 'Hey, keep making good pitches and keep pounding the strike zone and it's going to start going your way.' I'm going to try to stay as positive as I could."
Saunders seemed to be in trouble again in the third when he gave up a pair of singles to start the frame, but the left-hander was lights out after that, as he retired the next 14 Pittsburgh hitters.
Meanwhile, the D-backs continued to grind at-bats against Pirates starter Wandy Rodriguez, who managed to work his way out of trouble until the sixth.
With one on and two outs, Wil Nieves, who was making his first appearance since being claimed on waivers on Monday, hit a home run to left to put the D-backs up, 4-3.
Nieves hit a breaking ball, and by that point in the game he had seen just one fastball from Rodriguez.
"If you just go breaking ball after breaking ball, even if I'm looking for a fastball, I'm conscious, I'm slowing down and I can see it better," Nieves said.
Rodriguez fell to 7-11 on the season.
"Hey, man, I don't know what's going on for me," Rodriguez said. "To lose on only one [bad] pitch. ... I hung a breaking pitch [to Nieves] and he hits it for a home run. I feel bad. I think about [the pitcher being on deck]. That's why that home run for me is very bad, with the pitcher next. I tried to throw a good breaking ball, but I missed my spot and he hit the ball very well."
Kubel lined out softly in his second at-bat, and then flew out to center in the fifth. That at-bat left him steaming mad, and according to Gibson, he told his manager that his next time up he was going to homer to center.
That's exactly what he did, as he blasted a two-run shot to center in the seventh.
"He told you guys?" Kubel said with a sheepish grin. "I was saying this time I'm going to stay with it and hit it up the middle, preferably over the wall."