Harris English made the most of a lightning start to card a 62 and take the first round lead ahead of two time World Golf Championships winner Ian Poulter at the 2021 WGC-FedEx St Jude Invitational.
The American went out in 28 to match the lowest nine holes on the 2021 Race to Dubai and while he dropped two shots early on the back nine, a strong finish moved him to eight under at TPC Southwind.
Englishman Poulter carded a blemish free 64 to sit two shots back alongside European Tour affiliate member Carlos Ortiz and American pair Jim Herman and Matthew Wolff.
Major Champion Bryson DeChambeau was then at five under with fellow American Scottie Scheffler and Australian Marc Leishman for company, a shot clear of four home favourites in Daniel Berger, Sam Burns, Max Homa and Will Zalatoris.
English is a four time winner on the US PGA Tour, including at this event in 2013 and twice this season, but his victory in Memphis came before the tournament had World Golf Championships status, and he is still seeking a WGC breakthrough.
"Birdieing the first four holes is good all the time," he said. "It was just one of those rounds where you're hitting it where you're looking.
"Everything was working, you just kind of get in the zone. All you're thinking are positive thoughts, you're hitting good shots and hitting good putts so you just try and keep the gas pedal down.
"I'll just keep doing what I'm doing. It's my seventh time playing this course and this tournament so I feel I've got a good strategy.
"I've been working hard at home so I feel I'll just keep doing what I'm doing, keep hitting fairways and greens and see what happens."
English made a dream start with four birdies, sandwiching a 25 footer on the second and an up-and-down on the par five third with putts from inside ten feet at the first and fourth.
I'll just keep doing what I'm doing. It's my seventh time playing this course and this tournament so I feel I've got a good strategy
A 30 footer on the sixth was followed by a putt from around half that distance before he put an approach inside ten feet at the ninth to turn in 28.
He dropped shots on the tenth and 12th but bounced back with an approach to 11 feet at the 15th and two putts from just off the green at the par five next, before a stunning iron to five feet at the last helped move him two ahead.
Poulter won the WGC-Match Play in 2010 and WGC-HSBC Champions in 2012 but the win in China was his last European Tour victory.
Starting on the tenth, he put his tee shot to just inside ten feet for a birdie on the par three 11th and got up and down from the sand to make the most of the 16th.
He started his second nine in fine style with an approach to seven feet at the first and after making a two putt birdie at the third, he holed a 35 footer at the fourth to get to five under.
He looked in trouble at the eighth but chipped in for a third two of the day and got up and down from a bunker at the ninth to save par and complete a bogey free effort.
Fresh from representing Mexico at the Olympic Men's Golf Competition, Ortiz was also bogey free in his 64, while Herman and Wolff both combined a single dropped shot with seven birdies.
Leishman finished eagle-birdie-birdie to fly up the leaderboard, with DeChambeau dropping one shot with six bogeys and Scheffler recording two blemishes with seven gains.
