The achievement was a first for the 29-year-old Clements, who scored his lowest career round while also finding himself in the lead for the first time on the tour.
Yet he showed no signs of that going to his head after the round.
"I think you can lose tournaments on Thursdays, but you can never win them," Clements said. "I'm actually delighted with how I played today.
"A few tweaks I'm going to try and solve this afternoon, but for the main part I was absolutely delighted and looking forward to tomorrow and what that brings."
Clements scored birdies on three of his first four holes at Corales Golf Course at Puntacana Resort & Club, then shook off a bogey to reel off six birdies over a nine-hole stretch.
"Got off to a great start," he said. "I kind of just kept it going. I had a nice putt on 5, 6, somewhere around there, for bogey and it felt like (I) kept the momentum going. Yeah, just kept going through."
Like Clements, Cantero Gutierrez, who is 30, has never won on the tour.
Also like Clements, he had a memorable round.
Cantero Gutierrez began his day on the back nine and started with back-to-back bogeys. He erased that poor start with six birdies over a seven-hole stretch and then pocketed three more late to forge a tie for first place.
Low scores were contagious on a course with wide fairways, as six golfers are within a stroke of the lead after shooting six under.
Americans Austin Eckroat, Johannes Veerman, Jonathan Byrd and Gordon Sargent are tied with Spain's Alejandro Del Rey and Canada's Mackenzie Hughes.
Eckroat, who is currently ranked just outside the top 100, could pick up some valuable points this weekend with many heavyweights competing at The Open.
"When we saw we were going to be here, we said, well, someone's got to win it," Eckroat said. "Yeah, huge going into the rest of the season, a lot of points available, good momentum. A lot of good things going."
A total of 10 players are at five under, including Italy's Felippo Celli who provided one of the highlights of the day by holing out for eagle from 176 yards.
There are no Australians in the field.
