"Why [Bumgarner]?" Bochy said. "He's been swinging the bat pretty well, he's got power."
It was ultimately Bumgarner's eyes, and not his bat, that fueled the Giants' second comeback of the night.
Chapman got Bumgarner, who has five home runs on the season, to whiff on consecutive pitches to begin the plate appearance, with the radar gun at AT&T Park reading 99 and 101. The Giants' ace then took back-to-back balls, both north of 100 mph.
"He worked a great at-bat," Bochy said. "He kept that rally going. I've used him a couple of times in that situation and I knew he'd give us some good swings, and he did."
Bumgarner, who won a Silver Slugger Award last season, fouled off the fifth pitch before letting the next two pass for balls three and four, becoming the first pitcher to reach base against the Reds flamethrower.
"It's tough no matter who you're facing," Bumgarner said. "This is the big leagues, there's nothing easy about it, for sure. You've just got to try to lay off the balls and swing at strikes. That's really all there is to it, and I try to keep it as simple as I can."
The walk loaded the bases, and Chapman forced in a run when he hit the next batter, Ehire Adrianza, with a fastball. In the ninth, Chapman allowed two runs for his third blown save of the season, sending the game to extra innings, where Todd Frazier's leadoff homer in the 10th won it.
Prior to Bumgarner's plate appearance, Chapman worked an 0-2 count vs. 57 hitters in 2015, none of whom successfully received a free pass. The left-hander had struck out 41 of those 57 batters before the reigning World Series Most Valuable Player worked the seven-pitch walk.
"It's certainly a lot better than striking out or getting out or not doing anything productive," Bumgarner said. "Anything productive, that's all you can ask for."