Behind in the third set, the 18-year-old fought back to send home Croatian Nikola Mekti 6-3 4-6 6-4 just days away from the August 25 kick off at Flushing Meadows.
The 2014 first-round Australian Open winner fended off a massive collapse after giving away a 4-1 second set advantage to lose seven straight games before finally regaining his rhythm in the decider.
The world no.185 moves on for a date with fellow teenager Yoshihito Nishioka of Japan after his upset of fifth seed Horacio Zeballos.
12 aces helped Duckworth dispatch of Frenchman Axel Michon 6-3 5-7 6-2. He faces American wildcard Ernesto Escobedo in the next round. Rodionova edged China’s Lin Zhu 7-5 4-6 6-4.
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