The three British players in action on the first day of the boys' singles event at the US Open all progressed.
Jamie Baker posted the most impressive result, upsetting 14th seed Igor Sijsling of the Netherlands 6-3 7-5.
Tom Rushby followed his compatriot into the second round with a 6-3 7-5 win over Italy's Andrea Arnaboldi.
And Miles Kasiri, who reached the junior Wimbledon final in July, saw off Marcus Fugate of the United States in three hard-fought sets, 6-3 4-6 6-3.
Third seed Andrew Murray, also of Great Britain, along with his brother Jamie are in action on Monday.