Former world number one Adam Scott ended the opening round in a tie for the Safeway Open lead alongside Andrew Landry, while former NFL quarterback Tony Romo produced a fine display.

Scott carded a seven-under-par 65 for a share of the one-stroke lead after day one of the PGA Tour tournament in Napa, California on Thursday.

The Australian golfer was almost flawless at the Silverado Country Club, where Scott bogeyed one hole while posting an eagle and six birdies.

American Landry joined Scott atop the leaderboard thanks to his bogey-free performance, which included seven birdies.

Francesco Molinari – winner of the Open Championship in 2018 – and Matthew NeSmith are a shot off the pace following their first-round 66s.

Ex-Dallas Cowboys QB Romo posted a two-under-par 70 to be among 22 players tied for 29th position heading into the second round.

Romo – a four-time Pro Bowler who retired in 2016 – is appearing in just his fourth PGA Tour event.

The 39-year-old, who won the 2018 celebrity tournament American Century Championship – used five birdies to help come back from an up-and-down round.

Amateur Romo upstaged stars Justin Thomas and Phil Mickelson in the opening round of the Safeway Open, as well as defending champion Kevin Tway following his 71.

Thomas – winner of the 2017 FedEx Cup and US PGA Championship – experienced a mixed round with an eagle, three birdies and four bogeys for a one-under-par 71.

Five-time major champion Mickelson struggled in his three-over-par 75, which left the American with plenty of work to do.