There were many factors that may have been responsible for Hanna's low round - softened greens, forgiving rough, lady luck - but she thinks she knows what the secret was.
'I switched to cross-handed putting last week, and I guess it worked,' Hanna quipped.
Rain on Wednesday left the municipal course literally soaked, leaving greens more receptive than usual. Hanna took full advantage of the conditions during her early morning round.
Her bogey-free round featured nine birdies. She made birdie on the first hole of the day, the 351-yard par-4 10th and never looked back. Just two holes later, on the par-5 13th, the second year veteran two-putted from within 20 feet and narrowly missed an eagle putt opportunity.
'Shooting 63 is a great accomplishment for me,' said Hanna. 'I feel like I could have improved some too, because I missed a five-footer on No. 2, and I really think 18 should have been a birdie.'
Chances are you're wondering who Jen Hanna is.
She's a former Futures Tour player who made quite a splash at the beginning of the 2000 season. During the final round of the Firstar LPGA Classic, she finished in the top-10 for the second time in the 2000 season and shot a career low round of 64.
But the greatest high of her short yet tumultuous professional career was swiftly followed by an all-time low.
During the 2000 Subaru Memorial of Naples, her very first event on tour as a professional, Hanna played her way into the lead. It looked as if - with just two holes to go - this rookie would take home the win.
Then disaster struck.
Hanna, in the true definition of the expression, choked. She made bogey on both the 17th and 18th to finished tied for eighth and earning just $16,986.
It was a big learning experience for a rookie.
'I almost felt like I wasn't deserving of it. I thought my game wasn't ready,' she said.
Out of the 23 events she played in during the 2000 season, Hanna made only 12 cuts and $57,044. A win this week would mean the addition of $112,500 to her coffers and even more valuable confirmation that she believes she is now deserving of it.
Shooting 63 proved to be too great an accomplishment for the rest of the field on Thursday. Even with the advantage of the rain-soaked greens, scores fell at least two strokes short of that goal.
Annika Sorenstam carded a bogey-free first round of 7-under 65. She holds sole possession of second place. 'I was very happy with the way I played today,' said the Swede. 'I played very solid and had a lot of chances out there today. It seemed like every hole I had 10 to 12 feet for birdie.'
Sorenstam wasn't surprised by Thursday's results. 'This course is score-able, so I'm expecting low scores, especially with the rain from yesterday,' she said.
Michele Redman and Emilee Klein finished 6-under 66. Amateur Lorena Ochoa, one of two players to receive a sponsor's exemption, joined them late in the day.
Dorothy Delesin, Brandie Burton Akiko Fukushima, Lorie Kane and Dottie Pepper trail the lead by four strokes. All five players finished at 5-under-par 57.
Pat Hurst, who lost in the playoff last year, concluded her first round at 4-under-par 68
The weather is expected to remain sunny and warm on Friday. Subsequently, greens will firm up as the day wears on, making low scores increasingly difficult to attain. This, combined with Sorenstam nipping on the heals of a winless Hanna, should make for some exciting golf.