Miami - Venezuela's Jhonattan Vegas stayed out of trouble on the testing Champion course at PGA National, firing six birdies in a six-under 64 on Thursday to take a two-stroke lead in the PGA Tour's Honda Classic.

Vegas teed off on the 10th and played the tough back nine in four-under.

He rolled in three birdie putts from 14 feet or more, drilling a 16-footer at the par-three seventh.

But he said his iron play was the real key to his round, which put him two strokes in front of a quartet of players on 66 that included three major champions in Ernie Els, Zach Johnson and Lucas Glover along with Canadian Ben Silverman.

World number four Brooks Koepka headed a group of 13 players on 67 that also included Spain's Sergio Garcia, American Rickie Fowler, South African Charl Schwartzel and South Korean Lee Kyoung-hoon.

Defending champion Justin Thomas was in another big group on 68.

"Every time I come around this place and don't make a bogey it's pretty good," Vegas said of the Jack Nicklaus-designed course.

"I was able to drive the ball really well today. I hit my irons incredibly well.

"I only missed three greens and out of those three I left two within 15 feet of the hole."

Els, 49, and seeking to take his tally of PGA Tour titles to a round 20, overcame a double-bogey five on the par-three 15th, where he was in the water off the tee.

"That freaking 15th hole is no good at all on this golf course," quipped Els, who countered with six birdies. That included a birdie at his penultimate hole, the eighth, where he stuck his approach less than three feet from the pin.

"I've really been swinging it better lately and this is a golf course where you get it anywhere under par and you're really happy, even in benign conditions like this morning," Els said.

Els, who claimed his 19th and most recent PGA Tour title with his victory in the 2012 Open Championship, admitted the idea of No 20 was appealing, but said he wouldn't get ahead of himself.

"Obviously 20 is a great number," he said.

"It's late in my career, but I'll take any win now. I'm not thinking about it. I'm just thinking about tomorrow's round and so forth. But it would be magic."

Leading first-round scores on Thursday in the PGA Tour Honda Classic at PGA National in Palm Beach Gardens, Florida (USA unless noted, par-70)

64 - Jhonattan Vegas (VEN)

66 - Zach Johnson, Ernie Els (RSA), Ben Silverman (CAN), Lucas Glover

67 - Bud Cauley, Brooks Koepka, Charl Schwartzel (RSA), Anirban Lahiri (IND), Hank Lebioda, Adam Schenk, Rory Sabbatini (SLO), Roberto Castro, Bronson Burgoon, Sergio Garcia (ESP), Rickie Fowler, Billy Horschel, Lee Kyoung-hoon (KOR)

68 - Kang Sung (KOR), Ryan Armour, Patrick Rodgers, Ben Crane, Chesson Hadley, Cameron Smith (AUS), Justin Thomas, Keith Mitchell, Sam Saunders, Stephan Jaeger (GER)

Pleased with my start today, 4-under par 66 @TheHondaClassic. Made some nice putts out there & a good way to begin the Florida Swing, always one of my favourite little stretches @PGATOUR pic.twitter.com/IOWaCCuaJD

— Ernie Els (@TheBig_Easy) February 28, 2019