"He couldn't get on track. That's one of those games, it started out bad and gradually got worse."
The Giants lost the game, 13-2, and the series. They concluded the road trip with a 1-5 record and entered the All-Star break trailing Los Angeles in the National League West standings by a half-game.
Lincecum (3-10) gave up a two-run homer to Andrew McCutchen in the first inning and a solo shot to Neil Walker in the third. Things unraveled for him in the fourth, when a walk and three singles -- the last by Burnett -- led Bochy to remove his embattled starter from the game.
"You never want to say, 'Hey, I've hit rock bottom' or anything like that," Lincecum said. "When things are going as bad as they are right now, you kind of got to go out there feeling like you've got nothing left to lose.
"It's been terrible. It's a terrible feeling, feeling like you've let your team down. That's the hardest thing."
When reliever Clay Hensley replaced Lincecum in the fourth, the bases were loaded and the Giants already trailed by four. The Pirates got another run on a sacrifice fly by Drew Sutton and another still when Walker singled to center field.
Lincecum came into Sunday's matchup having given up nine home runs, second fewest on the Giants staff. The Pirates took him deep twice, becoming the fourth team to do so in 2012.
"I have to erase this, but obviously remember it and use it to know what I don't want to go through again," Lincecum said. "When you're the weaker link, you kind of look at that and it wears on you. You try your hardest to work out of it, and that's what I've got to do."
His opponent, Burnett, was as effective from the mound as he was at the plate, where he picked up his 10th career RBI and first since 2005. In facing the Giants lineup, Burnett (10-2) was simply dominant, giving up two runs and striking out five over 6 1/3 innings.
"A.J. was very efficient, very strong when we needed him to be strong," Pirates manager Clint Hurdle said.
The Giants mustered just four hits against Burnett. Half of them came in the seventh inning, when Pablo Sandoval sent a 3-2 pitch over the center-field fence. The big fly came with a runner on second and kept San Francisco from being shut out.
"We didn't swing the bats very well again," Bochy said. "Their guy, he's had a good year, and he pitched well."
Aside from Hensley, who entered during a sticky situation and wasn't charged with any runs, the performance by the rest of San Francisco's bullpen didn't exactly make for a bright spot in this one, either. Jeremy Affeldt gave up a run on three hits in the fifth, while Brad Penny surrendered three runs on three hits in the sixth. Only two of Penny's runs were earned. They are the first he has allowed while wearing a Giants uniform.
George Kontos let the Pirates tack on two more runs in the seventh. McCutchen's second homer of the game scored himself and Walker, who had picked up his fifth hit in the previous at-bat. Justin Christian's fielding error allowed another Pittsburgh run to come home in the eighth. It was the Giants' third error of the game.
As for Lincecum, he insists he's healthy. He made no excuses for Sunday's performance and said that while the All-Star break will give him time to relax, he'll be thinking about all that has gone wrong and how best to prevent it moving forward.
"We certainly didn't want to go into the break like this, limping the way we did, but now it's behind us," Bochy said. "We've got to regroup here. Hopefully, the days off will do that for us."