Garret Heath and Morgan Uceny won at Manchester's Great CityGames.
The Americans bring a strong field to this year's race in the heart of Manhattan.
The miler is hoping for a low-3:50s race on Saturday night.
It was his first race of the season.
Hard-luck Lolo Jones wins gold in record style at indoor track world championships. Written by: Matt Fitzgerald American hurdler Lolo Jones