Britain's Andrew Murray and Jamie Baker both advanced to the third round of the US Open junior event on Wednesday.
Third seed Murray, from Scotland, was hardly tested as he breezed past American Vahid Mirzadeh 6-1 6-2.
Fellow Scot, 18-year-old Baker, was made to work in the opening set of his encounter with Ukraine's Oleksandr Nedovesov but won through 7-6 6-4.
There was no such luck for Murray's older brother Jamie, who was beaten 7-5 7-5 by Argentine Eduardo Schwank.
The Murray brothers did well in the doubles competition, beating Spaniard Pablo Andujar and Juan Martin Del Porto from Argentina 6-1 6-2.