The British Masters champion had nine birdies, including four in a row from the 13th, despite needing on-course treatment for a neck problem, and rose 40 places into a tie for 11th.
He has six shots to make up on leader Jaco van Zyl in Antalya, but rediscovering his putting touch means he will approach the final two rounds with confidence.
“For me it (63) shows that there’s a low one out there for me. Two more of those and hopefully that will do the trick,” said the 21-year-old.
Van Zyl enjoyed a three-shot overnight lead after a brilliant opening 61 at the Montgomerie Maxx Royal and was seven clear after five birdies in his first 10 holes on Friday.
However, the 36-year-old then found water off the tee on the fourth and eighth to drop his only shots of the week so far and eventually signed for a 69 to finish 14 under par, two shots ahead of English pair Richard Bland and Chris Wood.
Another Sheffielder, Danny Willett, added a 70 to his opening 69. After starting with birdies at one and three, he went on to also birdie 11 but dropped a shot at 15.
Fitzpatrick says there was no major difference in his overall game to produce a 10-shot swing from days one to two.
He said: “I did actually play well tee to green (Thursday), it was just on the greens that I didn’t hole anything. Obviously that’s the scoring part, so that’s where it all counts.
“I just holed putts (today). I gave myself a lot of chances (Thursday), but holed nothing. I had 34 putts (in the first round) and I haven’t counted what I had (in the second round) but it was miles better obviously.”
France’s Victor Dubuisson, whose only victory to date came in the inaugural staging of this event in 2013, had a flawless 64 to sit alongside Paraguay’s Fabrizio Zanotti on 11 under, with Rory McIlroy and Alexander Levy on 10 under.
Former world No 1 McIlroy had needed a left-handed recovery shot on the 18th on Thursday and saved par on the same hole today, despite a penalty drop after driving into a bush, the 26-year-old recording a second consecutive 67.
“They’re as stress-free two 67s as I have shot all year,” said McIlroy, who has yet to drop a stroke and enjoyed a tremendous bit of luck on the fourth when his pulled drive was heading for the water until hitting a tree on the edge of the hazard.
“I definitely feel like there’s a lot more to come. I made a couple of good putts to save pars over the past couple of days, but for the most part I’m giving myself chances on most greens.
“I feel like I can hit the ball a little better. I can definitely get my wedges closer. I don’t feel like I need to put myself under any pressure to get off to a good start (in round three).
“Just play another solid round of golf and I’ll hopefully be in there with a shout going into Sunday.
“If I get myself up there, I feel like I’ve had a lot more experience than some of the guys up there on the leaderboard closing tournaments out, so I’d back myself. I looked at the leaderboard on the fourth green and at that point I think I was 10 behind. So to be only four behind isn’t much at all.”
South African Van Zyl, who has yet to win on the European Tour despite 13 victories on the Sunshine Tour, said: “Surprisingly enough I was not too anxious out there. I really enjoyed the moment, took every shot as it came and every opportunity when it was there.
“It’s a field of quality players and they have all played nicely to be here. To be in this position is really an honour and hopefully we can stay in the mix till the last nine holes on Sunday.”
Bland is also seeking a maiden European Tour victory and revealed his fiancee had provided some useful motivation midway through his round.
“I got told in the middle of the first fairway that I had sold my house and thought ‘All right, better try to pay for the new one,” the 42-year-old from Southampton said.
“I thought I was playing all right and just not doing anything. I couldn’t really get it close to the flag and then the back nine just kind of clicked.”