The 42-year-old Swede, who two months ago was coaching his daughter's softball team, birdied the last two holes Saturday to fire a five-under par 66.
Noren stood on eight-under 205 for 54 holes at Quail Hollow and was three strokes behind top-ranked leader Scottie Scheffler, his playing partner in Sunday's final group.
"It feels good. I got it together," Noren said. "(Time off) gave some good perspective, but I wish I would have played more golf leading up to this than I have."
Noren was sidelined last October with tailbone and tendon issues.
"It was just my tendon in my hamstring on the sit bone. It's a bad injury but you can still live a quite normal life because you have two other tendons that support it," Noren said.
"I could walk slowly and live a normal life. I could coach my kids. Spent a lot of time with the family. It has been quite nice. But I couldn't swing a club. I couldn't jump or run."
Noren knew he was in for a protracted recovery time.
"The bad part of it is that it takes a long time to heal and it was 90% torn. So I had that 10% left to make it heal back so I didn't have to have surgery," he said.
"If it was actually torn, I would not play right now. That was lucky but also bad at the same time."
The lucky part is that Noren was able to recover in time for the PGA. The bad part was it didn't leave a lot of time to prepare.
"As soon as I kind of could play, I thought I was in sort of the same form I was in before I got injured," Noren said. "But I'm still extremely - not surprised, but I'm fortunate to be in this position this early."
Noren, a 10-time European Tour winner, had his best finish in 39 major starts with a share of sixth at the 2017 British Open.
After a three-month off season and four months fighting to get back, Noren hopes the mental benefits might help keep him playing longer than he might have without the break.
"Maybe. I got some good perspective, like spending that much time in the middle of a career, hopefully I'll play a lot longer," he said.