SAN FRANCISCO — Braves rookie reliever Brandon Cunniff was charged with four hits and five runs in one-third of an inning Thursday, after previously allowing just two hits and three runs all season in 15 innings over 17 appearances.

The damage came in an eighth inning that turned into a debacle, with Cunniff and journeyman left-hander Donnie Veal giving up a total of six hits, six runs, one walk and one wild pitch, allowing the Giants to turn what had been one-run game into a 7-0 rout in the series opener.

Cunniff’s ERA jumped from 1.80 to 4.70 in one-third of an inning.

“It just got away from us really quick,” Braves veteran catcher A.J. Pierzynski said. “I mean, a leadoff walk, a groundball up the middle that goes off our second baseman’s glove on a nice try, and then a bunt for hit, and a bad hop to Simba (Andrelton Simmons). It just kind of got away from us real quick. But Brandon will learn from it. Hope he doesn’t get discouraged, and the next time he gets the ball in that situation, he’ll learn from it and get better.”

Cunniff had not allowed a hit all season by a right-handed batter – they were 0-for-30 against him – before Hunter Pence hit a two-run triple off him Thursday. The rookie’s troubles started when he walked No. 8 hitter Matt Duffy to start the inning.

Braves manager Fredi Gonzalez left Cunniff in after a left-handed pinch hitter Gregor Blanco followed the walk with a single, and leadoff man Nori Aoki, another lefty batter, followed that with a single. With another lefty due up, Joe Panik, Gonzalez left Cunniff in to face him, and Panik hit a two-run double.

Gonzalez stuck with Cunniff because he’s been effective against lefty batters, and situational lefty Luis Avilan has been inconsistent.

“There’s no defense for the first walk,” Gonzalez said. “It’s one of those things when you get a young player, but I felt really confident to put him in that position, because he’s done really well for us. I think yesterday was the first time that a right-hander got a base hit off of him, and he’s .130 against left-handers. All that stuff’s going through your mind. Their left-handed (hitters) hit left-handers; they’re in the .300s, if you look at their splits. Our left-handed situation is…

“Tomorrow, same situation, you run him back out there. That’s the only way, and hopefully the veteran guys in the bullpen say (to him), ‘Hey, you’ve got to have a short memory, and go back out there and pitch.’ Because we’ve seen him pitch, and pitch well. In (pressured) situations. So just keep running him out there.”