He sits in a much different position than three of his four previous appearances in the Arnold Palmer Invitational, when he missed the cut.
"Those 35-40 footers are luck, but if I keep making them inside 10 feet I'm going to be OK", he said.
"Maybe got a little aggressive there", he said. "I shed two layers, but I still got layers on".
Cink and Molinari persevered, each carding 2-under par 70.
Fowler, the world number nine, picked up four more strokes - while also saving his par from the water at 11, pants rolled up to the knees - and then landing an Eagle put on the par-five 16th.
But he walked off the sixth hole at Bay Hill on Saturday down a club. Several players capitalized, led by 22-year-old Englishman Matthew Fitzpatrick, who matched Grillo's 67.
Honda Classic victor Fowler started the third round at two-over and a distant 12 shots off the pace, but the world No.9 is now sitting pretty at five-under. This was where he would often greet players, or just admire their shots from afar. The scoring average of 73.7 Thursday is the highest during 17 previous PGA Tour events so far this season.
Sharing 58th place with McIlroy is Palmer's grandson, Sam Saunders.
It goes back to October 4, when Saunders showed so much poise and humility as he stood before thousands of golf's most important figures and spoke at Palmer's funeral service at St. Vincent College in Latrobe, Pennsylvania.
Chun, 22, has two majors on her resume as she also won the Evian Championship previous year.
Following a surprising cold front that hit Florida, temperatures will begin to rise Friday and into the weekend.
Grillo played Bay Hill past year.
Jason Day and Justin Rose also remain on the radar at three-under par.
The pristine yet challenging putting surfaces at Bay Hill will become only slicker and trickier in the warmer weather.
"If I had my hands out of my pockets for a minute or two, I would be freezing", Grillo said. "I think it could be all you want".
The 57-year-old Couples birdied five of the first seven holes and added four more on the back nine before bogeying the par-4 18th. I hit a few good shots, especially coming down the stretch. "The Argentine looked shaky at the start, needing a 9'1" par saver at the first and then swallowing bogeys at No. 3 and 4. "Playing in the fairway, that helps". Forget all that. He went ahead and knocked down the 71-footer for birdie to snag a share of the 54-hole lead at 11 under with Kevin Kisner. The Argentinian bogeyed consecutive holes at Nos.
"I played nicely", he said. "His presence is overwhelming".
Meanwhile, the most entertaining moment of the day wasn't actually a golf shot.
"I'm sure that was hard", he said.