Duckworth did not have to strain himself much to win the first set, but it was Purcell, who rallied to win 3-6 7-5 7-6 (5) in the final.
It took Nagal an hour and 22 minutes to secure a 6-1 6-4 win over Jay Clarke of Great Britain.
Nagal entered the tournament through the qualifying rounds, whereas Jung entered as a lucky loser.
