Jordan Spieth looked unstoppable Sunday afternoon at the CJ Cup Byron Nelson PGA Tour event.He signed for an impressive bogey-free 9-under 62 to jump 20 spots up the leaderboard and likely finish inside the Top 5. Spieth finished at 19-under overall.Even though Spieth never had a real shot at catching Scottie Scheffler, who is setting PGA Tour records this week, this low round was a victory for Spieth in its own right.It marked his lowest season score, previously a 65 at the WM Phoenix Open and the Cognizant Classic. The 62 was also his best round since 2021, which tied his career low."I've been stroking it well coming into this week, and I didn't have much go in in Hilton Head," Spieth said. "Statistically, I've been on a really good putting run, and I kind of got in a lull for Hilton Head and even into the first few days here. Luckily, today seemed to get out of it."The former Texas Longhorn made a birdie to start his day at the par-4 1st, and from there, it was like a switch flipped.Jordan Spieth Putter Catching FireSpieth noted that the first putt helped him a lot on Sunday."Honestly, seeing the putt go in the middle on No. 1 was nice," Spieth said after his round on Sunday. "It was only six or seven feet, but it was an uphill right-to-lefter. I was like, 'Wow, okay. I liked how that felt.'"He added three in a row on holes 4-6 and his fifth at the par-5 9th to turn in 31 strokes.Spieth made two more birdies on 11 and 12.He added his eighth of the day at the par-4 14th and finished off his round with on 18 to collect nine birdies total.The 13-time PGA Tour winner picked up +2.210 in strokes gained putting. It was not just his birdie putts that were big for him, but also those short ones for par that can sometimes cause him grief.He made over 91 feet in putts on Sunday, and +6.430 in strokes gained total.Spieth had wrist surgery last year, which caused him to miss most of the Fall PGA Tour season. It took the 3-time major champion some time to dust off the rust when he returned from injury, but he is slowly returning to form."The ultimate goal is consistent play, but it's not bogey avoidance or anything like that," he explained. "I'm not changing strategy. It's just that my mechanics are getting a little bit better each week. I'm able to do sufficient stuff, maybe that I wasn't able to do last year."The Texas native looked like his old self on Sunday, as it seems his game is finally coming around again.It is the perfect time for him to regain prior form.The PGA Championship tees off at Quail Hollow in 11 days. That is the sole major championship Spieth is yet to win. He won the Masters and the U.S. Open in 2015, before capturing the Open Championship in 2017.Rory McIlroy recently became just the sixth golfer ever to win the career Grand Slam. Spieth will look to join that list. If he plays the way he did on Sunday, that is a very real possibility.More Golf: Rory McIlroy Shares Unknown Heartfelt Masters Story with Daughter, Poppy