Martin Kaymer and Ian Poulter both made encouraging starts to the Florida Swing as two PGA Tour rookies led the way after the opening round of the Honda Classic.
Cody Gribble, winner of the Sanderson Farms Championship in October, and fellow Web.com Tour graduate Wes Bryan both fired six-under 64s to share the day one lead at PGA National, with Kaymer just one stroke adrift along with Anirban Lahiri.
Poulter returned a 66 and kept a bogey off his card to join a group of seven players including Rickie Fowler on four under, while defending champion Adam Scott was among 18 men to fire a 68.
Gribble enjoyed a run of five birdies in seven holes from the fourth and, although he dropped a shot at the 16th after three-putting from 50 feet, he bounced back with birdies at the final two holes to set the clubhouse target.
The left-hander soon had company at the top when Bryan, who posted a career-best tied for fourth at last week's Genesis Open, blitzed the front nine for five birdies to match Gribble's 64.
Kaymer got off to a hot start with three birdies over the first five holes, and a 20-foot putt dropped for another gain at the ninth to take him to the turn in 31, and he salvaged a par with a stunning flop-shot from the rough at the 11th.
The German narrowly avoided going out of bounds with his drive at the 13th when he ball took a fortunate bounce off a tree having landed on a cart path, and he did well to escape with a par before a poor approach to the 14th did cost him a shot.
But the Ryder Cup star got back on track when he pitched in for a rare birdie-two at the daunting 17th, and a crisp hybrid to the par-five last found the rear fringe to set up a comfortable closing birdie.
"I felt very calm over the ball," said Kaymer. "I enjoy the golf course. When you stand on the first tee, you don't feel like you need to make five or six birdies. It's a ball-striking golf course, but even level par or one over is a very good round.
"It was very soft and there was not much wind. Once you miss the fairway, it was actually okay from the rough because the greens are soft. I've not played the golf course in easier conditions."
Lahiri went one better at the 18th as he nailed a 25-foot putt for eagle to join Kaymer on five under, while Poulter was delighted to hand in a flawless card which featured an eagle at the third - his 12th - after he drilled a superb 265-yard second to six feet.
The Englishman followed that up with birdies at the next two holes, and he parred safely in to remain just two off the pace alongside Fowler, who had five birdies and a lone dropped shot.
Scott Stallings was a shot further back after a remarkable finish to his 67, making a hole-in-one with a perfect eight-iron at the 184-yard 15th and adding birdies at 16 and 18 to move from one over to three under in just four holes.
English pair Paul Casey and Tyrrell Hatton were well placed on two under with Scott and Ryder Cup team-mates Sergio Garcia and Rafa Cabrera Bello, while Masters champion Danny Willett carded an erratic 69 which included a double-bogey at 17 which he followed with an eagle at the 18th.