Monday, it was a three-run homer by Hunter Renfroe and a solo shot by Austin Hedges that sent Corbin and the D-backs to a 4-2 loss at Petco Park.
In the six games against the Cubs, Astros, Mets, Giants and Rockies (twice), Corbin had a 0.64 ERA.
So why the struggles against a Padres team that is at the bottom of the National League in runs scored?
"They're a heavy right-handed-hitting team," D-backs manager Torey Lovullo said. "There's some quality at-bats. And they battled. That's not to say anything against the rest of the guys that he faced, but they have waited out certain pitches in certain locations. Let's face it, tonight wasn't one of Patrick's best days and I think he'll be the first to admit that. I just think they do a good job of waiting him out, waiting for a mistake and not missing it."
From Corbin's perspective, it came down to a pair of mistake pitches that wound up in the seats.
"Those two mistakes on the two homers today," Corbin said. "Just got to keep the ball in the park there, make a better pitch."
The pitch to Renfroe was supposed to be a sinker that ran away, but instead the ball cut a little bit and wound up almost right down the middle.
But while Renfroe's blast drove in three, it was the Yangervis Solarte at-bat just before that really hurt.
Solarte jumped ahead 2-1 and then fouled off five straight pitches before taking two more balls to draw the two-out walk.
"Solarte worked a pretty good at-bat," Corbin said. "I thought I made some decent sliders that he fought off and worked a walk. And then I just made the mistake there early for the three-run homer. It's just frustrating."
Steve Gilbert has covered the D-backs for MLB.com since 2001. Follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.