Rory McIlroy at the seventh hole in the first round of Thursday
Mackenzie Hughes narrowly missed in a lap of 59 and number one in the world, Rory McIlroy registered an impressive seven-under-63 as the pair set the pace at the Travelers Championship.
Hughes' Canadian putt eventually fell short after a 10-under par round of 60 with 10 birdies.
McIlroy, the four-time winner of Northern Ireland, carded an eagle, six birdies and a bogey for his 63.
American fivefold main winner Phil Mickelson is in contention after a 64.
The event continued despite three individuals who tested positive for coronavirus.
Cameron Champ, Graeme McDowell & # 39; s Caddy Ken Comboy and Brooks Koepka's Caddy Ricky Elliott have the virus and withdrew from the tournament in Cromwell, Connecticut.
PGA Tour Commissioner Jay Monahan said the news acted as a "grim reminder" to comply with security measures.
McIlroy started on the 10th and was three below for his nine-hole opening and one that came in better.
Tyler Duncan and Michael Thompson finished sixth with fellow Americans Bryson DeChambeau, Russell Henley and Tyler McCumber who all placed 65s.