The world No.1162 carded a flawless eight-under 63 to take the clubhouse lead at Royal Queensland on Thursday, one clear of rising Perth star Lee.
The 25-year-old played with freedom just days after missing a maiden DP World Tour card by one shot in the final stage of qualifying school.
Joel Moscatel Nachshon is the surprise clubhouse leader at the Australian PGA Championship. (Jono Searle/AAP PHOTOS)
He just missed a long birdie putt on the 18th that would have eclipsed Jed Morgan's mark set during his romp to the title in early 2022.
"I didn't know what was the record, we just played our golf," the wide-smiling Spaniard said.
Unperturbed by his near-miss at a European tour spot, Moscatel Nachshon is content to toil on a lower-tier satellite circuit unless he can earn passage with victory at the $2 million Brisbane event.
"It was so fun ... nothing (there was no secret); it was a crazy day, we were so present, enjoying our golf," he said of him and his caddy.
"I know it (the prize) but we still have to play three more days of golf."
There were no smiles from defending champion and tournament favourite Cameron Smith (two-over 73), who lamented his inconsistent iron play as he drifted well off the pace.
"It was frustrating, upsetting ... I really couldn't get anything going ... just crappy," Smith said.
Lee made five birdies on his way home to set the early pace and upstage playing partner Smith in front of a bumper gallery despite their 6.10am tee time.
Having recently earned full PGA Tour status, the Perth talent had just as many fans gathered for his autograph following a superb first round in scattered showers and gusty wind.
Active on social media, Lee's catch-cry of "Let Him Cook" has been lapped up by punters who followed his dominant round in Brisbane.
"I did see him, took a picture with him ... definitely pretty cool that supporters go to that length," Lee said of a fan wearing a t-shirt emblazoned with the phrase.
"I was pretty nervous which I haven't really felt in a while before the round but that's good for me.
"I'd rather not get too comfortable ... I feel I'm good enough to win the tournament and play good wherever now.
"I've had that pressure on me at some tournaments and not been able to capitalise."
John Lyras signed for 65 while Adam Scott (66) managed five birdies in a six-hole blitz either side of the turn, then made up two more shots on the final three holes as his tilt to end a nearly four-year title drought grew legs.
He just missed a putt for eagle on the seventh, settling for a birdie after driving off the deck from 270m with precision.
Two-time champion Adam Scott shot an opening-round five-under 66 at the Australian PGA Championship. (HANDOUT/PGA OF AUSTRALIA)
Scott rated his wedge play better than ever before but warned he'd need plenty more to contend at the course he's been a member of since he was 11.
"Hopefully it sets the tone but if you're not five-under this morning it's going to be a long week to get to 20-under," he said.
"You've got to chip away at it and I'm kind of on par really, for that kind of target, because it's going to get close to that score."