Pedro Alvarez hit a tiebreaking single in the eighth inning as the Pittsburgh Pirates beat the St. Louis Cardinals 5-3 on Sunday to take a 2-1 lead in best-of-five NL division series.

Alvarez pulled a grounder into right field that scored pinch-runner Josh Harrison from second base. Russell Martin followed with a sharp RBI single against reliever Kevin Siegrist, who took over after Carlos Martinez (0-1) faltered.

The go-ahead single was the latest big hit by Alvarez. He homered in the first two games against St. Louis and is 4 for 10 with four RBIs in the series.

Alvarez also kept the Pirates' famous flag flying high in October. “Raise the Jolly Roger!” is the rallying cry for this wild-card team, now one victory from its first postseason series win since Willie Stargell, Dave Parker and the “We Are Family” gang won it all in 1979.

“We're continuing to surprise a lot of people, I believe. We're continuing to show people that we're not done, that we're not just happy to be in the postseason,” star center fielder Andrew McCutchen said. “We're fighting to win a World Series.”

Heady territory for a club that had endured a record 20 consecutive years of losing coming into this season.

Mark Melancon (1-0) picked up the win despite allowing Carlos Beltran's tying home run in the top of the eighth. Jason Grilli worked the ninth for a save.

Charlie Morton is set to start for Pittsburgh in Game 4 on Monday against rookie Michael Wacha.

Beltran finished 2 for 3 with three RBIs. His 16th playoff home run moved him past Babe Ruth for eighth place in postseason history.

“It's a must-win tomorrow for us,” Beltran said. “Hopefully we can come here tomorrow, take care of business, win and go play the last game at home.”

Beltran's shot temporarily silenced a rocking crowd at PNC Park. It also set the stage for another dramatic win by the Pirates.

McCutchen led off the eighth with his second hit, a double to left. But the NL MVP candidate unwisely tried to advance on Justin Morneau's grounder to shortstop and was an easy out at third.

Harrison ran for Morneau and moved up when Marlon Byrd walked. St. Louis manager Mike Matheny turned to a lefty in Siegrist to face the left-handed Alvarez. The Pittsburgh slugger tied for the NL lead with 36 homers during the regular season, but hit just .180 against lefties.

“I just knew it was going to be a tough matchup,” Alvarez said. “I've seen him a couple of times before. I haven't had much success. He's a pitcher with good stuff _ great stuff. He threw me a couple of fastballs out over the plate.”

One too many, as it turned out, and Alvarez singled between first and second. Martin then fouled off a squeeze bunt before lining a hit to left that gave Grilli more than enough cushion.

The game was a rare nail-biter between two clubs that spent the summer shadowing each other in the race for the NL Central title. Coming into Sunday, only five of the previous 21 matchups between the two were decided by two runs or less.

After blowouts by each club in St. Louis, there wasn't much room to breathe in front of a frenzied, black-clad crowd looking for a repeat of Pittsburgh's giddy 6-2 romp over Cincinnati in the wild-card game last Tuesday.

The Dodgers were hosting Atlanta later Sunday with their NLDS locked at 1-1. (AP)