Day one digest: 2020 U.S Open Championship

Justin Thomas led the way on day one but former Ryder Cup partners Rory McIlroy and Thomas Pieters were right in the mix.

Here is everything you need to know from the opening round at Winged Foot Golf Club.

Nappy factor working wonders for McIlroy and Pieters

Becoming a dad for the first time does not obviously lend itself to keeping your golf game sharp. There is the lack of sleep, the reduced practice due to baby-related commitments and the mental fatigue that comes with a new arrival. However, the 'nappy factor' theory, which suggests new fathers enjoy improved performance on the course, has been around for decades and Thomas Pieters and Rory McIlroy appear to be the latest beneficiaries. Pieters, whose partner Stephanie recently gave birth to daughter Florence, carded a four under 66 to lie one behind leader Justin Thomas. McIlroy and wife Erin welcomed daughter Poppy just a fortnight ago and fatherhood clearly suits the Northern Irishman, as a 67 gave him a strong start to the week.

Oosthuizen and Westwood in contention again

Louis Oosthuizen and Lee Westwood know how to put themselves in the mix at Major Championships, and the pair were at it again in New York. Oosthuizen, the 2010 Open winner and one of only seven players to have finished runner-up in all four Majors, carded a three under 67. That was matched by Westwood, who has 12 top-five finishes in Majors. Expect both to be loitering on the leaderboard throughout the week.

Amateurs impress 

American amateur Davis Thompson threatened a fairytale script when he reached four under before eventually signing for a 69. That was matched by compatriot John Pak, with Chun An Yu level par to set up an intriguing race to be the week's leading amateur.

Kaymer continues resurgence

Remarkably Martin Kaymer's eight shot win at the 2014 U.S. Open remains his last foray into the winner's circle. However, the German has been in good form recently, finishing third at the Belfry and second at Valderrama on his last two starts. A one over 71 put two-time Major winner Kaymer in the frame to feature once more.

Cabrera Bello in contention

Spain's Rafa Cabrera Bello came into the week without a top-ten finish this season. However, while form is temporary, class is permanent, and a two under 68 put the Ryder Cup star in the top ten after the opening day.