PUNTA CANA, Dominican Republic -- Tony Romo fell apart on the back nine and made his PGA Tour debut with a 5-over 77 in the Corales Puntacana Resort and Club Championship.

The former Dallas Cowboys quarterback shot even par on the front nine before a bad stretch of three bogeys and a double-bogey toward the end of his round. He was 14 shots behind Brice Garnett, the early leader, who opened with a 63.

Romo started his round off with back-to-back bogeys on the first two holes but then made birdies on Nos. 4 and 5. He answered a bogey at No. 7 with a birdie on No. 8 and finished the front nine at even par. To start his back nine, Romo made a putt of at least 25 feet to make par but had difficulties on holes Nos. 13-16.

Romo missed the fairway on four straight tee shots, taking -- but not needing -- two provisional shots on Nos. 15 and 16 only to find his original shot. He parred his final two holes, coming up short on birdie attempts both times.

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"That's just nerves, and hopefully you can get that out of the way," he said of his early nerves after his round. "I kind of knew that the most difficult part really would be the opening holes just in the sense of getting yourself comfortable and acclimated to the environment. Then in some ways it's as simple as just getting the speed of the greens down. I just left too many putts short today."

Romo said he had a difficult time committing to his tee shots on the back nine, which led to his issues.

"I think I feel comfortable," he said. "Just a couple of swings as I got to the back nine that you want back, but I'll be more committed. I'll know the lines a little bit better and hopefully I come out and go low."

Romo now works as an NFL analyst for CBS Sports. He received a sponsor's exemption into the tournament, which is held the same week as a World Golf Championships event in Texas.

Among early starters, only Guy Boros at 79 had a higher score. The 53-year-old Boros is playing his first PGA Tour event in three years.

ESPN's Todd Archer and The Associated Press contributed to this report.