The Canadian goes into Round Two at Kiawah Island in South Carolina in the lead.
Canadian Corey Conners leads the US PGA Championship ahead of round two at Kiawah Island.
He shot a 5 under par opening round of 67 in windy conditions.
Padraig Harrington is the best of the Irish trio.
The European Ryder Cup captain made an eagle on the 11th hole en route to a 1 under par round of 71.
Shane Lowry double bogeyed the 17th as he carded a 1 over par round of 73.
Tournament favourite Rory McIlroy has work to do from 3 over par.

Ireland And England Will Meet Next February To Kick Off 2027 Six Nations
Tolka Park Stages The Dublin Derby Between Shelbourne And Shamrock Rovers
Conor McGregor Not Included In White House Fight In June
Ireland's Men And Women Hockey Teams Book Their Spot At This Year's World Cup
Ireland To Train Collectively Today Ahead Of Next Saturday's Six Nations Clash
Monday Morning Sports Update
Kildare Hurlers Seal 2027 Division 1B Place
Kildare Hurling Team vs Carlow