The weekly playoff format means Lowry is now under pressure in today's round.
Shane Lowry is 1 over par following the opening round of the FedExCup playoffs.
The Open Champion had a mixed bag of five bogeys and four birdies in signing for a round of 72.
Rory McIlroy however will go into the second round of the Northern Trust five shots off the lead.
The world number 3 carded a 2-under par round of 69 in Boston yesterday.
Harris English, Kevin Streelman and Cameron Davis head the field on 7-under par.
The other Irishman in the field, Graeme McDowell is 6 over.
McIlroy doesn't feel at the peak of his powers right now.
Midlands Sides Continue U20 Leinster Football Campaigns This Evening
We're All Rooting For Shane Lowry - Donagh McArdle
Offaly Keep Minor Hopes Alive With Win Over Longford
Shane Lowry Paired With Dustin Johnson And Jason Day For Opening Masters Round
Laois And Offaly Venues To Host Leinster Football Semi-Finals
Westmeath And Laois Win Big In Leinster Minor Hurling Championship
Buccaneers Round Off AIL Season With Victory
Athlone Town Begin All Island Cup With Victory
Offaly Secure Win Over Laois In Leinster U20 Hurling Championship
Athlone Town Claim Bragging Rights In El Classico
There Should Be A Big Crowd For Offaly Laois Next Weekend - Brian Gavin
Buccaneers Travel To Galwegians For Final Game Of AIL Season
Athlone Town Look To Maintain Unbeaten Home Record
Laois And Offaly Face Off In Leinster U20 Hurling Championship
Patsy Joyce Gearing Up For World Boxing Cup In Brazil
Westmeath's Jessica Hennessy Helps Bournemouth Lift Silverware
Athlone Town Kick Off All Island Cup
Westmeath U20s Bounce Back While Laois Drop Out
Laois, Offaly And Westmeath In Action In U20 Football Championship