Mackenzie Hughes carded a brilliant 10-below 60 to direct the Tourists Championship as Rory McIlroy produced a robust start out.
Hughes holed 10 birdies in the 1st spherical at TPC River Highlands in Connecticut to open up up a three-stroke direct on Thursday.
The Canadian, who has struggled because returning from the coronavirus-enforced break, manufactured six birdies on his 1st 9 holes in advance of finding up shots at the second, sixth, seventh and eighth holes.
Hughes is a few shots obvious of entire world No. 1 McIlroy, Xander Schauffele and Viktor Hovland.
McIlroy combined an eagle and six birdies with just a solitary bogey to get started with a seven-beneath 63.
Though Hughes is nicely crystal clear, the relaxation of the leaderboard is congested, with another 6 gamers a shot further more back again in a tie for fifth.
Phil Mickelson, Sergio Garcia, Michael Thompson, Tyler Duncan, Noh Seung-yul and Louis Oosthuizen opened with 64s.
Jordan Spieth made a reliable start off with a 3-underneath 67, to be along with Jason Working day and Justin Rose amongst other folks.
Spieth, winless since 2017, was 4 below through nine holes just before a combined again nine, which integrated bogeys at 10 and 18.
Also in a tie for 33rd is Abraham Ancer, who manufactured the shot of the day with a gap-in-one at the 16th.
Meanwhile, previous environment No. 1 Dustin Johnson opened with a 1st-round 69, two pictures better off than countryman Justin Thomas.