A five-run outburst and another sound start by Phil Dumatrait carried the Pirates past the Arizona Diamondbacks, 6-4, this afternoon before 22,222 at PNC Park.

Dumatrait allowed two runs and four hits in 5 2/3 innings to improve to 3-3. The team is now 6-2 when he starts.

"I'm just glad to be doing my part," Dumatrait said. "I got a lot of help from my defense and my bullpen."

Closer Matt Capps came on for the ninth with a two-run lead and recorded his 14th save in as many chances. The Pirates also got terrific defense from the infield corners by Adam LaRoche and Jose Bautista.

LaRoche, who entered in a 4-for-39 slide, had a double and two singles.

"He looks like he's coming around," manager John Russell said.

"I hope so," LaRoche said. "I know I'm feeling more comfortable."

Arizona took a 1-0 lead in the second when Conor Jackson scored from third on a passed ball charged to catcher Raul Chavez.

The Pirates scored five times in the fourth off Doug Davis, beginning with back-to-back doubles by LaRoche and Bautista. Chavez followed with an RBI single, Jack Wilson hit a sacrifice fly and, after Nate McLouth walked, Jason Bay lined a two-run double into the left-field corner.

That was it for Davis, tagged with five runs, seven hits and four walks in his 3 2/3 innings. It was his worst outing of the season, one in which he missed six weeks for treatment of thyroid cancer.

Mark Reynolds homered off Dumatrait in the fifth, and he ran into some trouble in the sixth by putting two aboard with one out. He froze Chris Young with a third-strike fastball on the outside corner for the second out, after which Russell replaced him with Tyler Yates.

Yates was erratic in walking his first batter, then running up a 3-0 count with bases loaded for Reynolds. But he got two strikes on Reynolds, who then grounded out to short.

Arizona pulled within 6-4 on Reynolds' second home run, a two-run shot in the eighth off Franquelis Osoria.

The Diamondbacks have taken two of three in the series, with the finale tomorrow.