PITTSBURGH -- The Diamondbacks were flummoxed by Erik Bedard's dominance on Monday night.

They didn't get much help from him afterward, either. To Bedard, it was simple.

Bedard allowed two hits over seven innings, and the Pittsburgh Pirates opened a season-long 11-game homestand with a 4-0 victory against Arizona.

"That's just what you try to do -- make some good pitches, get some outs and get the hitters back out there," Bedard said. "And that's what I tried to do."

Bedard did not walk a batter and faced only one over the minimum, striking out five. He retired 17 in a row until his final batter, Paul Goldschmidt, singled. Goldschmidt was thrown out at second base trying to stretch the hit by left fielder Starling Marte to end the seventh.

"I don't know; he just stayed off the barrel somehow," Diamondbacks centerfielder Chris Young said. "I thought we had a pretty good approach with him; we just couldn't get anything going."

Bedard (6-12) leads the majors in losses but lowered his home ERA to 2.38. Pittsburgh has won 23 of its past 29 games at PNC Park.

"He pitched exceptional tonight," Pirates manager Clint Hurdle said. "He pitched to four spots, he got the ball inside, he mixed in his breaking ball for strikes, he got it for chase, he worked with a very good tempo and rhythm tonight. You can't pitch much better than that."

Jason Grilli and Chad Qualls each worked a perfect inning to preserve the shutout, the Pirates' sixth this season and second in the past week.

Andrew McCutchen had two hits and scored two runs for the Pirates, who began the day 4½ games behind Cincinnati in the National League Central.

"We broke out an old fashioned baseball game today: Pitching and defense," Hurdle said. "We had one run, and we added on a little bit late."

Rookie Wade Miley did not allow an earned run over six innings for Arizona, which has lost three in a row. Goldschmidt had both Diamondbacks hits.

Arizona entered the game having scored 106 runs since July 18, most in the majors in that span. But they were shut out for the second time in three days and committed three errors.

"They outplayed us, they out-executed us," Diamondbacks manager Kirk Gibson said. "It hurts, but we've got to find a way to get back on a good run."

Golschmidt was the only Diamondbacks player to reach base. He doubled leading off the second and ended the seventh with a single before being thrown out at second.

Bedard, who had lost six of his previous seven decisions, struck out Miguel Montero with Goldschmidt at third and one out in the second.

McCutchen manufactured a run with his speed -- and some shoddy Diamondbacks defense -- in the fourth. He led off with a single to center, but he took off for second when Young bobbled the ball.

McCutchen might have been thrown out at second but Young's throw was not handled cleanly by shortstop Willie Bloomquist. The ball got away from Bloomquist, and McCutchen took off for third.

Two Arizona errors were charged on the play, and Gaby Sanchez followed with an RBI groundout.

"I started it off with no outs, and we were able to play some small ball and get that one run in," McCutchen said. "That's something that we really needed."

It remained 1-0 until the Pirates broke the game open with a three-run eighth by way of four consecutive singles and Rod Barajas' sacrifice fly. Hits by Neil Walker and Travis Snider scored McCutchen and Sanchez.

Miley (12-7) allowed six hits and a walk and had two strikeouts.

"I felt all right," Miley said. "I kind of got into some trouble and had to battle a little bit... I wasn't executing, but we were able to keep it to one, so it wasn't bad."

Notes

• The Diamondbacks claimed C Wil Nieves off waivers from the Colorado Rockies and placed C Henry Blanco on the disabled list before the game. The 40-year-old Blanco has a sprained left thumb and was traveling back to Arizona for an MRI to see if he had a ligament tear.
• McCutchen is hitting .480 (37 for 77) in his past 21 home games and is hitting a majors-best .443 against left-handed pitchers.
• Pittsburgh improved to 11-4 at home against a left-handed starter.
• The second of three left-handers Arizona will start against Pittsburgh during this series, Patrick Corbin (3-4, 3.60) is scheduled to pitch Tuesday. RHP Jeff Karstens (4-2, 3.70) will attempt to win his fifth consecutive decision for the Pirates.