Duckworth came from a set down to beat Arnaldi 5-7 6-3 6-2 7-6 at the US Open. He won it on the strength of his serve, finishing with 15 aces to Arnaldi's five and winning 83 service points to 76.
Duckworth broke for an early 2-0 lead in the first set, but Arnaldi hit back at 2-3 and again at 6-5 to take it 7-5. Duckworth levelled the match with a break at 3-5 in the second, then took the third with breaks in game one, at 1-4 and at 2-5; Arnaldi's reply at 2-4 was not enough. Arnaldi led by a break at 3-1 in the fourth, Duckworth answered at 4-3 and won the fourth-set tiebreak to close it out.
Duckworth's key number was his break-point work: he saved 11 of the 15 break points he faced and converted six of his own, while Arnaldi saved 13 of 19. He also edged the return battle 52-50, adding to his 15-ace performance.