Dustin Johnson entered the par-5 17th in Round 1 of The Northern Trust at 4 under par. Playing competitor Brooks Koepka was at 2 under.
When they exited, Koepka led DJ by three.
Koepka, who is trying to overtake DJ for world No. 1, made eagle at the 581-yard hole.
Johnson made triple bogey, thanks to a wild tee shot hooked out of play.
Triple bogey for DJ.— PGA TOUR (@PGATOUR) August 23, 2018
From T2 to T17. pic.twitter.com/JHwBsnkZzL
One hole, five-shot swing.