PLAYA DEL CARMEN, Mexico – Sometimes the best shots are the ones you don't even see go in. That was certainly the case for LPGA rookie Melanie Green, who carded a stunning hole-in-one she didn't even realize she'd made, propelling her to a 6-under 66 and a share of the first-round lead at the Riviera Maya Open.

Playing in just her first full season on tour, Green found herself in dreamland on the par-3 15th hole. Her 7-iron landed about 20 feet short of the cup and rolled gently in. While the announcers erupted, Green remained blissfully unaware.

"I was like, 'OK, great shot. Phenomenal.' Grab the putter – normally hit the green, grab the putter, it's a cool effect," Green recalled with a laugh. "Then we're walking up and I'm looking at the green. There is no ball."

In a moment of rookie confusion, she handed her caddie the putter and reached for a wedge, thinking she'd missed left. Her caddie, however, spotted the pitch mark and peered into the cup. There it was – her ball, marked with a distinctive cross.

"I walk up there and all I could see was the cross. I was so excited," Green said. "Yeah, thought I just went way left. But whatever. Good bounce."

That ace sparked a sizzling front nine of 30, with five birdies to go along with the hole-in-one. A lone bogey on her final hole kept the round from perfection, but Green wasn't complaining. She shares the top spot at 66 with Brianna Do, who took advantage of calmer morning conditions with four birdies in her first five holes.

Do, who also dropped a shot at No. 9 before settling in with three back-nine birdies, credited recent windy conditions for sharpening her game. "I think for some reason playing in the wind helps me kind of just play golf, instead of like playing a golf swing," she said.

Meanwhile, world No. 1 Nelly Korda showed no signs of letting up after her dramatic major victory at The Chevron Championship just four days ago. Despite battling gusty afternoon winds that made El Camaleon's fairways look even tighter, Korda opened with a solid 68, putting her just two shots off the pace. The red-hot American, who returned to the top of the rankings last week, continues to look every bit the player to beat.