Besides Sai (47), who is lodged at Lajpore Jail here since 2013, the court held four of his aides, including two women, guilty of various offences.
Sai was convicted under IPC sections 376 (rape), 377 (unnatural offences), 323 (assault), 506-2 (criminal intimidation) and 120-B (conspiracy). Of the 11 accused, six were acquitted.
Additional Sessions Judge P S Gadhvi will pronounce the quantum of punishment. The minimum punishment for rape is 10 years in jail, while the maximum punishment is life imprisonment.
Sai's aides-Dharmishtha alia Ganga, Bhavna alias Jamuna and Pavan alias Hanuman--were held guilty for being part of a conspiracy. Sai's driver Rajkumar alias Ramesh Malhotra was held guilty under IPC section 212 (harbouring an offender).
Ganga and Jamuna, also called "sadhika" (women disciples), were accused of putting the victim in illegal confinement and thrashing her at Sai's behest. They were also accused of trying to brainwash her into agreeing to have a relationship with Sai.
Hanuman, a loyal "sadhak" (disciple) of Sai, was accused of abetment, including taking the victim to Sai's room.
Surat Police had filed a 1,100-page charge sheet against Sai in 2014.
In 2013, after Asaram was arrested for raping a girl in Rajasthan, two Surat-based women accused Asaram and his son of sexual exploitation.
The elder sister accused Asaram of sexual assaults between 1997 and 2006 when she lived at his Ahmedabad ashram.
The younger sister accused the godman's son of sexual assaults when she lived at Asaram's ashram in Jahangirpura area of Surat between 2002 and 2005.
Sai was arrested from Delhi-Haryana border in December 2013.
When he was in jail, Surat Police claimed to have unearthed Sai's plans to bribe police officers, doctors and even judicial officers to weaken the case against him.
Asaram, meanwhile, was convicted by a Jodhpur court for rape. The trial against him in the case filed by the Surat-based woman is going on at a Gandhinagar court.