(Sports Network) - Arizona southpaw Doug Davis makes his fourth start since a much-publicized bout with cancer today when the Diamondbacks visit PNC Park for the third game of a four-game weekend series with the host Pittsburgh Pirates.

Davis made two starts in early April before an absence of more than a month, during which he had a cancerous thyroid removed after it had been diagnosed during spring training.

He defeated Atlanta in his return to the majors on May 23, allowing five hits and a run over seven innings of Arizona's 11-1 triumph.

Davis is 0-1 with a no-decision in two starts since, giving up 15 hits and seven earned runs in 11 innings.

He is 6-5 in 19 career starts against the Pirates with a 4.98 earned run average.

Fellow lefty Phil Dumatrait is looking for a fourth consecutive strong start for Pittsburgh.

In his last three starts, in which he's picked up a win, a loss and a no- decision, Dumatrait has given up just 14 hits and three earned runs in 18 2/3 innings.

The former first-round draft pick of the Boston Red Sox reached the majors with the Cincinnati Reds last year and was 0-4 in six starts with a 15.00 ERA.

He has never faced the Diamondbacks.

On Saturday, Chris Snyder led off the ninth inning with a home run off reliever John Grabow, his sixth of the season, giving Arizona a 4-3 victory.

Chris Young had two hits and drove in two runs for the Diamondbacks, who scored three times off starter Tom Gorzelanny in the first inning.

Pittsburgh rallied with a run each in the third, fourth and fifth innings off Dan Haren to tie the game.

Nate McLouth had two hits, including a home run, for the Pirates, who also got a round-tripper from Jason Bay.

Juan Cruz was the winner for Arizona after pitching a scoreless eighth. Brandon Lyon earned his 14th save of the season after allowing a hit and a walk in the ninth.

These two clubs split six games in Pittsburgh last year.