SAN FRANCISCO -- As Dauri Moreta jogged in from the visitor's bullpen, the first of four relievers who’d combine to blank the Giants’ hot bats and lock in a much-needed win, Oracle Park’s sound system began blaring a familiar tune: “Renegade” by Styx.

“I heard that and I was like, ‘Wait, no way. You’re a few innings too early,’” laughed David Bednar, who uses the Pittsburgh anthem as his walk-out song.

“Renegade” may not have played on time Tuesday, but Bednar did not seem to mind as he, Moreta, Colin Holderman and Jose Hernandez pitched a combined 4 2/3 scoreless innings in relief, shutting the door inning after inning to lift the Pirates to a 2-1 win over the Giants.

“I think everybody you hand the ball to is going to give us a really good chance of winning because we have a lot of guys down there who throw nasty stuff and go out there and compete,” Bednar said.

Bednar (1.29 ERA), Hernandez (2.25), Holderman (2.18) and Moreta (1.82) have served as pillars of Pittsburgh’s bullpen all season long, Hernandez and Moreta holding it down in low- to medium-leverage situations and Holderman and Bednar shutting it down in the eighth and ninth. Following Tuesday's performances, those four have a combined 1.89 ERA across 90 1/3 innings with 113 strikeouts to 23 walks. Add Yohan Ramirez (1.50 ERA) into the equation and the Pirates quietly have themselves one of the National League’s more daunting bullpens.

“The guys we throw out there all have really, really good stuff,” said Jason Delay. “To be honest, it’s difficult to catch. … If it’s hard to catch, it’s got to be hard to hit.”

Holderman and Moreta extended a pair of personal streaks as neither has allowed an earned run this month. Holderman hasn’t allowed a run in his last nine outings, tossing 8 2/3 innings with 14 strikeouts to one walk, while Moreta hasn’t allowed an earned run in his last 12 outings, throwing 14 2/3 innings with two unearned runs and 21 strikeouts to three walks.

For Bednar, in particular, Tuesday represented his first save opportunity in over a month, his last being on April 29. Bednar remained familiar with high-leverage situations over the course of May -- on Sunday, Bednar pitched in the ninth inning of a tie game against Seattle -- but on Tuesday, Bednar finally had another opportunity to slam the door on an opponent.

“I’m just staying locked in every single day no matter what,” Bednar said. “I’m always ready to pitch and ready for that situation. Whenever the phone rings, I’m dialed in and ready to go down there.”

Moreta was the bullpen brigade’s first representative, entering the ballgame with one out and runner on second in the fifth inning. The right-hander wasn’t all that sharp, unable to consistently land his slider for strikes, but he executed just enough pitches to get out of the inning unscathed. Moreta began his outing by walking J.D. Davis, but got Michael Conforto to fly out and Mitch Hanniger to ground out.

“I think the one thing that Moreta has done is we’re seeing more strikes,” Shelton said. “He’s commanding the ball. He’s commanding the slider. He’s throwing it in all counts, which is really important.”

Hernandez, like Moreta, came into the game with a duck on the pond, entering the sixth with a runner on first and one out, but the rookie southpaw needed just three pitches to escape the frame. Patrick Bailey smoked a line drive right at first baseman Connor Joe, and with Blake Sabol initially breaking for second base on contact, Joe calmly jogged over to first and tapped on the bag to complete the inning-ending double play.

“Jose doesn’t have any fear,” Shelton said. “He comes in, he goes right after guys. He gets the top of their order with some really good hitters and has to execute pitches. He continues to impress.”

Holderman took the baton from Hernandez and built a bridge to the ninth inning without much of an issue. The right-hander induced an inning-ending forceout to complete the seventh, then worked past Conforto’s leadoff infield single to record a scoreless eighth inning.

While Moreta, Hernandez and Holderman all inherited a runner, Bednar entered the ballgame with a blank canvas in the ninth, striking out Bailey and Brett Wisley swinging and getting LaMonte Wade Jr. to fly out to paint his 10th save of the season.

“I think it just speaks to the way that he handles himself and the preparation he does,” Shelton said. “Credit to him, credit to [bullpen coach Justin Meccage] for making sure that he stays on task.”