Second seed Joshna retired hurt after the fourth game of her semi final clash against her fourth seeded rival Samantha Cornett of Canada, who later lost in the final to American top seed Latasha Khan, according to information available here.
Joshna, globally ranked 31, had built up a two-game lead before Samantha - world no 56 - stormed back.
In the fourth it appeared that the Indian player had a self-inflicted injury and she was unable to continue in the fifth and retired hurt.
Joshna, who was level 11-5 11-9 9-11 2-11 when she quit the contest against Samantha due to her injury, had earlier brushed aside Elpiniki Clement (USA) 11-1 11-5 11-8 in round one and then ousted seventh seed Nayelly Hernandez of Mexico 11-5 11-8 11-8 in the quarters.
The Mexican player, ranked 68th, had ousted India's up and coming Aparajitha Balamurukan, a qualifier, 11-7 11-5 10-12 11-8 in round one.
Eventual 38-year-old winner Latasha, who won the 7th WISPA title of her career and is ranked 30th in the world, got past another young Indian player - qualifier Anaka Alankamony - 11-5 13-11 11-9 in the opening round.