Updated

Pittsburgh, PA (SportsNetwork.com) - Tony Sanchez's RBI double in the seventh inning proved to be the difference as the Pittsburgh Pirates edged the St. Louis Cardinals, 2-1, in the rubber match of a three-game set at PNC Park.

With the score knotted at 1-1, Pedro Alvarez worked a leadoff walk. Adam Wainwright fanned the next two batters, but Sanchez hammered a double to right-center to score Alvarez all the way from first.

"I had to almost trick myself into thinking I was ready for this, when really I'm not," said Sanchez. "My heads spinning a million miles a minute and an ace like Adam Wainwright on the mound and I'm supposed to drive in Pedro (Alvarez) from first with two outs in the (seventh)? Yeah, you trick yourself, fake it until you make it."

Mark Melancon worked a perfect eighth and Jason Grilli spun a scoreless ninth to earn his first save of the season.

Neil Walker also had an RBI double for the Pirates, who start a nine-game road trip on Tuesday against the Cubs.

Edinson Volquez allowed just one run on three hits and one walk while fanning four over 5 2/3 innings. Tony Watson (1-0) worked 1 1/3 perfect innings in relief to earn the win.

Jon Jay stroked an RBI triple for the Cardinals, who fell to 3-3 on the season.

Wainwright (1-1) allowed both runs on five hits while striking out seven over seven innings to absorb the loss.

"When you're playing tough teams, rivalry teams like we did today, especially here in Pittsburgh, they're going to be really tough. It comes down to a couple of plays that turn the game," Wainwright said.

Pittsburgh broke through in the fourth when Walker laced an RBI double to right field. Andrew McCutchen reached on a one-out double to right and came around to score easily when Walker smacked a double that bounced off the wall.

The Cardinals were unable to get a baserunner past first through the first five innings, but finally got on the board in the sixth on Jay's run-producing triple.

Game Notes

Starling Marte, who reached on a bunt single in the sixth, has reached base safely in all 18 of his games against the Cardinals, hitting safely in 17 of the 18 tilts ... Volquez hasn't lost to the Cardinals since May 22, 2012 ... The Pirates are 3-0 when leading after seven innings this season ... The Cardinals recorded just 17 hits in the three-game set.