Justin Thomas posted the seventh 59 in PGA Tour history at the Sony Open on Thursday.
The 23-year-old star capped his incredible first round with an eagle, his second of the day, at the par-five ninth hole.
Thomas started the round Thursday with an eagle on the par-four 10th hole.
He then bogeyed the 11th, but it was smooth sailing from there, playing the next 16 holes in 10 under.
When his final putt reached the bottom of the cup, Thomas held a five-shot lead over a group of players at six under.
Thomas fought off Hideki Matsuyama last week at the Tournament of Champions to earn his third PGA Tour win.
He has two wins already this season, having already taken out the CIMB Classic, where he was defending his title.
He joined Al Geiberger, Chip Beck, Stuart Appleby, Paul Goydos, Jim Furyk and David Duval as the only players to shoot 59 in a PGA Tour round.
Furyk became the first player ever to shoot 58 last year at the Travelers Championship.