Inbal Pezaro recovered from a slow start to give Israel its first medal of the 2012 London Paralympics.
The five-time Paralympic medallist added a bronze to her collection after a miraculous comeback in the 50m freestyle final.
Pezaro had finished runner-up in her heat at the Aquatics Centre.
Other Day One highlights saw Yoav Valinsky finish sixth in the Men's 100m Backstroke.
The Israeli came home in 1:34:12 in heat two.
Elsewhere in the pool, Inbal Ganapol Shwartz finished her 100m Breastroke in sixth place in a time of 1:44:43.
Shay Siada was defeated in his opening match in Group C. The Israeli was beaten in straight sets to Korean Sang Il Choi, 11-6, 11-8, 11-6 at the ExCel North Arena.