PITTSBURGH (AP) -- For the first time this week, the Diamondbacks bullpen backed up a strong Arizona start. Chris Young provided the offense with one swing.
Young hit a two-run homer in the eighth inning, four Arizona pitchers combined for a five-hit shutout and the Diamondbacks snapped a three-game losing streak with a 2-0 win over the Pittsburgh Pirates on Thursday night.
Young pulled a 2-0 pitch from Chris Resop (2-2) down the left-field line just inside the foul pole for his 12th homer of the season. Reliever Micah Owings (2-0) legged out a one-out infield single before Young's hit.
"The pitching staff's been doing such a good job," Young said, "and the last couple games we haven't been able to put the runs up for them, and we've kind of put them in some situations they probably shouldn't have been in in the first place. We probably could have put up more runs."
Diamondbacks' starters had allowed only two runs over 19 1-3 innings in the previous three games - but a combination of lack of offense and some blown saves conspired to result in the losing streak.
Thursday, Josh Collmenter continued his stellar rookie season, pitching five-plus shutout innings. This time, Joe Paterson , Owings and David Hernandez finished up the Diamondbacks' sixth shutout of the campaign by allowing only one hit in four innings.
Two days after allowing five runs without retiring a batter, Hernandez earned his second save with a perfect ninth.
After holding opponents to a .208 average and having a 2.34 ERA in May, Arizona's bullpen came in to Thursday having allowed 18 earned runs in 19 June innings.
"(Blown saves) are going to happen sometimes," Owings said. "But our guys down there, we've got a great bullpen and a great staff, and it's a long season and you'll go through some ups and downs."
The Pirates (30-31) won four of their previous five and six of eight. But they missed out on a sweep - and on an opportunity to move above .500 this late in the season for the first time in 12 years.
Young, Justin Upton and Miguel Montero each had two hits for Arizona, which had lost five of eight since winning 15 of 17.
Young, who has a six-game hitting streak, homered for the second time in the series.
"I think he's getting better at what kind of pitch he wants to hit in that situation," Diamondbacks manager Kirk Gibson said. "He put a good quick swing on it, and it was big."
Collmenter allowed four hits and two walks with four strikeouts. He has a 1.12 ERA in 48 1-3 innings (1.12 ERA), having allowed only four earned runs in six starts. He has pitched 14 consecutive scoreless innings.
"He's been a challenge for everybody so far," Pirates manager Clint Hurdle said. "He's made a statement. If you look at the batting average against coming in, it was way over .200 (.158).
"It's hard to square up balls when a guy is throwing strikes low in the zone with that kind of a downhill plane on them."
But Collmenter was matched by Jeff Karstens , who continued to shine as Pittsburgh's fifth starter after beginning the season in the bullpen. Karstens allowed four hits in seven shutout innings.
In his past four home starts, Karstens has allowed three runs in 25 2-3 innings (1.05 ERA) - but he has earned a win in only one of those outings.
"I didn't feel so good the first three innings - I had a lot of guys on," said Karstens, who retired 14 of his final 15. "Last year, though, I would have crumbled and we would have had an early deficit but I'm feeling more comfortable this season and a more confident, too."
The Pirates' Andrew McCutchen drew a walk with two outs in the first and went to third when Neil Walker followed with a single. But he was the only runner to advance that far for either team until Young's homer.
For the second consecutive game, however, two starters had exceptional outings that resulted merely in no-decisions. Wednesday, Paul Maholm and Zach Duke combined to allow one run in 13 combined innings.
Notes: Diamondbacks closer J.J. Putz was not available due to a mildly stiff back. Putz downplayed the significance of it and insisted he would be ready Friday. ... Karstens intentionally walked No. 8 hitter Gerardo Parra in the second, the first batter to walk against him in 26 innings. Karstens did not walk another batter in the game. ... Aug. 15, 1999 is the last time Pittsburgh has had a winning record this late in the season. ... In two career starts against Arizona, Karstens has pitched 16 scoreless innings.