Jones hit 13 of 14 fairways and 15 greens in regulation as he fired seven birdies with one bogey in his opening effort.

He walked off the course with a three-stroke lead, but was joined on six-under at day’s end by American Joel Dahmen and Ireland’s Paul Dunne.

“I hit a lot of quality iron shots and got it close to the pin,” said Jones, who is coming off a tie for 13th at the Valspar Championship.

He said he benefitted some from an early start, with the wind picking up in the afternoon.

“Six-under was a good score – that was probably the worst score I could have shot today,” Jones said.

Dahmen teed off on 10 and was one-under through 12 holes, but he roared home with birdies at five of his last six holes.

Dunne also opened on 10 and was one-under at the turn before making five birdies coming home.

The top trio was one stroke clear of South Korean Im Sung-jae in the tournament played opposite the elite WGC-Match Play in Austin, Texas.

Former Dallas Cowboys quarterback Tony Romo, making his third US PGA Tour start in the same event where he made his first last year, carded a seven-over 79.

Romo, who competed on a sponsor exemption, bogeyed three of his first four holes followed by a triple-bogey on the eighth. He was one-over on the back nine with a bogey at 13 and was unable to convert No. 8 to finish the front nine 6-over.

The 38-year-old was 1-over on the back nine with a bogey on No. 13.

Romo was unable to convert a birdie chance at the last.

“I think I played much better this year so far coming into the tournament than I did last year and I also think I’ve improved a lot in certain areas,” said Romo, who was in the spotlight but also in third-from-last place.

“But sometimes the score doesn’t show that so there’s disappointment with that I feel like.”

“I think I’m going to play a little better tomorrow. There (are) some good signs of life.”