Indian pace spearhead Zaheer Khan will hold the key for the No 1 Test side to bounce back in the ongoing series against South Africa, former captain Sourav Ganguly said here today.

"A lot will depend on the Zaheer factor to win the Durban Test. Toss will also play a crucial role in Durban. But we need to bat consistently. I strongly hope that India will bounce back," Ganguly said.