PITTSBURGH -- When he walked through the doors of the visiting clubhouse at PNC Park on Thursday morning, the most pressing issue for Micah Owings was what he was going to have for breakfast.

That changed a few minutes later when he was summoned into D-backs manager Bob Melvin's office and told there was a good chance he would be starting that afternoon's game instead of Brandon Webb.

"A lot started running through my mind, and then I just went back to the fact that I've just got to go out and try to do the best that I can to try to help the team out and not try to do too much," Owings said.

OK, so maybe he didn't try to do too much, but he sure did plenty, as he shut down the Pittsburgh offense and drove in three runs of his own in the D-backs' 8-0 win.

The win snapped Arizona's three-game losing streak and sent the D-backs into a regular-season-ending series in Colorado with no worse than a one-game lead over the Padres in the National League West and a two-game advantage over the Rockies and Phillies in the NL Wild Card race.

With that many teams fighting for postseason spots, it means there are numerous scenarios for how things can shake out, but for the D-backs, it's very simple: win and they're in.

Thursday's game didn't count more in the standings than any other, but its emotional impact cannot be overstated. With the Rockies, Padres and Phillies surging, and the D-backs having lost two straight to the last-place Pirates, Arizona needed this one to stem the bleeding.

"It's a very big win for us," D-backs manager Bob Melvin said. "We take it day-by-day, but obviously winning that game as opposed to losing that game, confidence-wise, we feel a lot better about what's going on going [to Colorado]."

The D-backs got on the board in the first inning thanks to a solo homer from Stephen Drew, and they tacked on three in the second, one of which came on an RBI double from Owings.

The rookie right-hander wound up going 4-for-4 at the plate, with three doubles and three RBIs. A "one-man wrecking crew," Melvin called him.

"It was nice to just get back in the box," Owings said. "It had been a week or over a week. Anytime I get in the box, I love getting in there. It's just another way that I can help the team, and I enjoyed it."

And he should. After all, he's now hitting .339 with a .695 slugging percentage in 59 at-bats this year. Owings has four homers to his credit, including two in one game during an August start in Atlanta.

"How impressive was his two-hit shutout the last time? Pretty impressive. This is even more impressive for me."

-- Bob Melvin, on Micah Owings

"Micah's offense is a joke," outfielder Eric Byrnes said. "He takes [batting practice] twice a week and steps up and rakes big league pitching. It seems like he's on [every pitch]. It's fun to watch."

Owings also did plenty of damage on the mound, as he worked 6 1/3 shutout innings before being lifted following an 18-minute rain delay.

That performance came on the heels of a two-hit shutout he threw against the Giants on Sept. 18 and one day before he was scheduled to start against the Rockies in Colorado.

Considering he had thrown a light side session Wednesday, Melvin wanted to talk with Owings to make sure he felt OK about starting if they decided to push Webb to Friday.

"We wanted to make sure there was conviction in him, or we wouldn't have done it," Melvin said. "The first thing he said was, 'Let's go, let's do it.' How impressive was his two-hit shutout the last time? Pretty impressive. This is even more impressive for me."

And even more important, too, for Owings' teammates.

"[It was] huge," Byrnes said of the win. "You know Colorado has been playing very well, so for us to have our ace going [Friday], it gives us a lot more confidence going in there."