Brooks Koepka made a strong start to the Phoenix Open as he heads into day two in a tie for third at five under par, with the four-time major winner looking to put an "embarrassing" fall from grace behind him.

Koepka has not won a tournament since succeeding in Phoenix a little under a year ago – while he impressed at the PGA Championship in May, finishing joint-second, Koepka is not happy with how the past 12 months or so have gone.

He teed off in Arizona ranked 20th in the world, something of a far cry from spending 47 weeks at number one across 2018 and 2019 – three of his four major wins came in those years.

Koepka, rarely one to mince his words, feels ashamed of his slide, even if he puts it partly down to injury.

"That's embarrassing to be 20th, I feel like," he said after his first round on Thursday.

"A lot of it has to do with injury, man. I've been hurt, on the sidelines. Not playing, playing through injury, you can't compete with guys out here.

"It's nice to be somewhat healthy and get out here, and I mean, I'm not too worried about it [the ranking], it will bounce back up."

to end the day @WMPhoenixOpen pic.twitter.com/rCjg7VdDjc
— PGA TOUR (@PGATOUR) February 10, 2022

Indeed, there was nothing embarrassing about his performance at TPC Scottsdale on day one, his six birdies – offset by a single bogey – putting him right near the top of the leaderboard.

Nevertheless, he still has a plenty of work to do.

Lee Kyoung-hoon is one shot better off thanks to a glorious showing after the turn, playing the front nine five under par after starting on the ninth hole.

But leading the way is a surprise contender: 24-year-old Sahith Theegala, who is competing as a sponsor's exemption.

Theegala has a one-shot lead over Lee, though he had to finish his round while putting on his 17th hole of the day as play was suspended due to bad light.

Additionally, his next shot when he resumes in the morning will be a 16-foot putt for par, so his lead may not last for long.

A host of familiar names are not too far behind those leading the way, with Xander Schauffele, Louis Oosthuizen, Patrick Cantlay, Jon Rahm and Bubba Watson among a large group on four under.

Jordan Spieth is three shots further back.