The wide receiver scored a fourth-quarter touchdown to give the NFC West side their second win of the season.
The 30-year-old told reporters: "You know you're a playmaker, you're used to being involved.
"I'm not one to ever complain or say anything. That's just not my demeanor. I just said to myself, 'when I get my opportunity I have to capitalise'.
"That was some ugly ball in the first half. I'm so thankful. Guys played their tail off. It was great to get a team victory."
Fitzgerald has 245 receiving yards and three touchdowns so far this season.