"That team is so good at hitting mistakes, it seems like every time I mess up they make me pay for it," Bumgarner said. "The pitch to Goldschmidt, that was a pitch I wanted to throw. It was pretty impressive him hitting that. I threw it right where I wanted to throw it. I guess it wasn't a very good pitch selection."
The left-hander served up two homers to the D-backs on Friday and allowed five runs, four earned, over six innings to snap his five-game winning streak.
Bumgarner also allowed two home runs to Arizona in his first start -- and only other loss -- of the season on April 7. In his five other outings this year, all wins, he gave up just one long ball total.
"I don't mind going here, I like this stadium, I like Arizona," Bumgarner said. "But for some reason, this team is so aggressive, when you make a mistake, they make you pay for it. If you make pitches, then you'll be fine. I tried to make pitches, but there were times when I didn't do that."
Friday was only the third time in 40 starts since the beginning of 2011 that the 22-year-old surrendered five extra-base hits in a game.
"He only made a couple mistakes," Giants manager Bruce Bochy said. "We didn't help him out, though, and that came back to haunt us."
The manager was referring to three defensive miscues the Giants made throughout the game.
In the third inning, shortstop Brandon Crawford committed an error to start the frame to allow Gerardo Parra to reach base. He eventually came around to score to tie the game at 1.
"I didn't need to rush it, it was hit hard, I had plenty of time," Crawford said. "It's a play I need to make every time."
The other two plays weren't ruled as errors, but a line drive off the glove of Crawford and a fly ball to Brett Pill that dropped each ended up costing the Giants.
The Giants lead the Majors with 35 errors.
"This ballpark, that lineup, you can't give them extra outs; we did that," Bochy said. "You'd like to think you're going to break out at some point."
On the other side, D-backs rookie starter Patrick Corbin delivered the best outing of his young career, allowing only one earned run on three hits over seven innings.
"These guys swing early sometimes, so if you make good pitches, it can work in your favor," D-backs manager Kirk Gibson said of the Giants. "If you make bad pitches, they get to you."
Friday began on a high note for the Giants when Melky Cabrera put the club on the board with a home run on a 2-0 fastball to left field in the first inning. The solo shot extended the outfielder's season-high hitting streak to nine games.
Tied at 1 in the fifth, Bumgarner gave up a leadoff double to Willie Bloomquist and almost got out of the inning without allowing a run, but Miguel Montero hit a fly ball to left field that turned around Pill and fell just short of the wall to score the go-ahead run.
"He's done alright out there," Bochy said of Pill. "But he doesn't have a lot of experience out there."
The next batter, Goldschmidt, compounded the damage with his two-run homer to leave the Giants trailing, 4-1. Goldschmidt's only other long ball this season also came against the Giants, on Opening Day off Tim Lincecum.
Bumgarner again was touched up in the sixth when A.J. Pollock connected for a solo home run, the first of his career.
"The two pitches that went for home runs were mistakes, but he's been so solid," Bochy said. "Occasionally you hope you pick up your pitcher, you can't be perfect every time out. Our margin of error isn't very big right now, and it probably puts more pressure on the [pitchers]."