Tony Romo authored an early highlight, but the former quarterback ultimately succumbed to some difficult conditions at the end of his opening round at the AT&T Byron Nelson.

Romo played his entire NFL career for the Dallas Cowboys, and he is a member at Trinity Forest which is hosting the event for the second consecutive year. That local knowledge paid off on the par-5 seventh hole, where Romo chipped in from in front of the green for eagle to reach 2 under on his round and give the partisan crowds plenty to cheer about.

But that proved to be the last highlight on an otherwise difficult day, as Romo made a double bogey two holes later endured a five-hole stretch from Nos. 13-17 in which he was 5 over. Romo ultimately signed for a 5-over 76, which exceeded expectations in Las Vegas where the over/under was set at 77.5, but it left him ahead of just four players in the 155-man field.

"Couple of the tee shots really cost me just because they're penal in those areas. You can't miss them there," Romo told reporters. "The separation between these guys is the ability to do it for long stretches, consistency. I think just a few tee shots really cost me the round today."

Romo plays to a scratch handicap and is making his third career PGA Tour start as an amateur, having missed the cut each of the last two years in the Dominican Republic. While he was listed as a 10,000-to-1 longshot, Romo was a popular bet this week: the Westgate Las Vegas SuperBook received more bets, both in terms of individual wagers and total money wagered, on Romo than on any other player in the field.

He'll have his work cut out just to make the cut with cooler temps expected Friday morning, but Romo remains optimistic about the gains his game has made in recent months.

"You work hard enough to put yourself in a position to hopefully continue to improve. I've improved from two months ago," he said. "I've got to continue to get more consistent and trust it. I think sometimes a little bit out there there's a trust factor of letting it go. When you play at the highest level of sport, you're going to let it go and play intelligently. Their swings are freed up."