Top seed Joshi beat 5/8 seed Khalil Alhassan of England 9-11, 11-4, 11-5, 11-6 in the boys final, while Dabke, seeded down the order at 9/12, scripted a shock 11-7, 11-4, 12-10 win over second seed Serena Daniel of the US in the corresponding girls title round.
Ananya sailed past Sofia Arseniev of the US in the opening round.
Then, in a spectacular giant-killing run the Indian went on to scalp 5/8 seed Franka Vidovic of Croatia 11-2, 11-4, 11-6 in the pre-quarter-finals, 3/4 seed Maia Pannell of England 11-5, 11-1, 11-7 in the quarter-finals and top seed Chukwu Chinyere of Hungary 11-5, 12-14, 11-7, 11-8 in the semi-finals.
Cologne Cup winner Joshi, who earned a first round bye, warmed up with straight sets wins over Belgium's Bjarne Schaillee, Yaseen Elsebaie of Egypt and compatriot Shreeman Raghavan.
In the semi-finals that featured three Indians, he beat compatriot Arnaav Sareen 9-11, 11-6, 8-11, 11-6, 11-7, after trailing 1-2, and finally overcame Alhassan who prevented an an all-India final with a 11-9, 11-9, 12-10 win over Kanhav Nanavati in the other semi-final.