The New York Open is in its second year after taking over from Memphis in this slot.
The ATP 250 event is now one of the biggest events of the early spring period following its one from Memphis.
Kevin Anderson won it last year but opted against trying to defend it with John Isner the highest-ranked player followed by Frances Tiafoe.
Bernard Tomic is also in action though as he looks to recover from his dip.
New York Open results
John Isner vs Bernard Tomic
John Isner – bye
Bernard Tomic bt Lukas Lacko 6-4 6-2
Adrian Menendez-Maceiras vs Christopher Eubanks
Jordan Thompson bt Noah Rubin 6-7 7-5 6-1
John Millman – bye
Guillermo Garcia-Lopez vs Bradley Kahn
Denis Istomin vs Mackenzie McDonald
Reilly Opelka vs Adrian Mannarino
Paolo Lorenzi bt Tennys Sandgren 7-6 6-7 6-4
Peter Polanksy vs Ryan Harrison
Brayden Schnur vs Jack Mingjie Lin
Steve Johnson – bye
Sam Querrey vs Lloyd Harris
Ivo Karlovic vs Radu Albot
Ramkumar Ramanthan vs Jason Lung
Frances Tiafoe – bye