Phoenix, AZ (SportsNetwork.com) - Starling Marte's RBI single in the ninth inning was the difference as the Pittsburgh Pirates topped the Arizona Diamondbacks 2-1 in the second of a three-game set on Saturday.

Tied at 1-1 with two outs in the final frame, Neil Walker doubled to deep left off Addison Reed (0-1) and came home after Marte hit a grounder past a diving Cliff Pennington at shortstop into left field for an RBI single.

Tony Watson (1-1) earned the win for tossing a scoreless eighth and Mark Melancon followed suit in the ninth for his fifth save of the season.

"You just have to go out and challenge them," Watson said. "Make your pitch and let them put it in play and let our guys do the work behind me."

Walker both doubled and scored twice and Pedro Alvarez knocked in a run with a double for the Pirates, who won their fourth straight game.

Pittsburgh starter A.J. Burnett surrendered one run on five hits and two walks with four strikeouts over seven strong frames.

Tuffy Gosewisch drove in Arizona's lone run with an RBI single and starter Rubby De La Rosa gave up one run and four hits and fanned eight in seven innings of work for the Diamondbacks, who dropped the series opener 4-1.

"He did a nice job tonight," Diamondbacks manager Chip Hale said of De La Rosa. "That's what we expected when we traded for him."

Chris Owings singled with two outs, stole second and rounded third on Gosewisch's line-drive single to right for a 1-0 Arizona lead in the second.

In the fourth, Walker hit a one-out double down the right-field line and moved to third on a groundout. Alvarez followed with an RBI double to right to tie the game.

De La Rosa set down the next 10 batters and Brad Ziegler tossed a flawless eighth.

In the home half, Ender Inciarte and A.J. Pollock got aboard with a pair of singles with no outs off Watson and moved up a base on Paul Goldschmidt's groundout. Wilson got out of the jam by getting Mark Trumbo to pop out in foul territory and striking out Aaron Hill.

Game Notes

Ziegler set the all-time club record with 254 appearances, surpassing Jose Valverde's previous mark ... Walker extended his hitting streak to eight games ... The Diamondbacks have posted nine straight quality starts for the first time since an 11-game streak from Sept. 12-22, 2008 ... Pittsburgh has won eight of its last 11 games in Arizona, dating back to April 17, 2012 ... Pirates left-hander Francisco Liriano will oppose Diamondbacks righty Jeremy Hellickson in Sunday's series finale.