"Tonight, I'll take the blame for that," Pelfrey said after falling to 0-3. "These guys gave me a lead and I gave it right back. That can be demoralizing, and that's my fault."
On the strength of run-scoring singles by Tyler Saladino and Jose Abreu, the White Sox jumped out to a 2-0 lead in the third. But the Twins answered with three in the fourth to quickly flip the script.
Jorge Polanco started the rally with a leadoff single to center and then stole second base. Max Kepler followed with a single to drive in Polanco and cut the deficit in half. Designated hitter Kennys Vargas then crushed a 390-foot home run to right field to give the Twins a 3-2 lead -- all before Pelfrey could get an out in the inning.
"It's never good to give up three, but especially after we score two," Pelfrey said. "I'm pretty disappointed in myself for that. That kills the team."
The right-hander believes the reason for his sudden drop off is simple: command.
"I came out for the fourth and I thought Polanco, I thought that was good hitting," Pelfrey said. "I thought it was a pitch that I executed fairly well and, obviously, good hitting.
"On Kepler, that ball was supposed to be in and it ended up being up and away, and ended up down the line. Then on Vargas, terrible pitch. It was right down the middle and kind of flat. He's got a lot of power and he, obviously, hit it."
Just like that, Pelfrey's impressive outing against his former team was gone.
"I think we were passive early and took some good fastballs to hit the first time around," Twins manager Paul Molitor said. "But he was throwing that front-door two-seamer to lefties and was throwing his forkball pretty well.
"But we got the first guy on with Polanco there and it seemed like once he pitched out of the stretch, we took advantage of that."
Despite giving up three runs in 4 2/3 innings to see his ERA rise to 5.21, Pelfrey saw some positives in his fourth start.
"For the most part, I thought my stuff was good," he said. "I probably would have liked to have thrown more strikes with the split and the curveball. There were so many lefties over there, I thought I did a good job of commanding in for the most part. But obviously, that pitch to Vargas was almost right down the middle and ruins the evening.
"Obviously, I need to get deeper in the game. As good as this bullpen's been, I can't ask them to pick up four innings every time I pitch. That's frustrating on my part."