Resuming on 352 for three, overnight batsman S Badrinath, who started the day on 62, Ravi Jangid (83) and all-rounder Shrikant Wagh (81) helped the team register a huge total before declaring the innings.
Although Vidarbha lost three wickets including Badrinath for 159-ball 89 that consisted of eight fours and a six, in the morning session, Jangid and Wagh coupled well to enable the hosts cross 550-run mark.
For Saurashtra, Kamlesh Makvana ended with figures of four for 122.
In reply to Vidarbha's mammoth score, Saurashtra lost opener Bhushan Chauhan (4) and one-down batsman Makvana (0) cheaply, to be reeling at 20 for two in 17 overs at the close of day's play.
Wagh accounted for both the wickets that fell today.
At stumps, Sagar Jogiyani was batting on 13 and Cheteshwar Pujara was yet to open his account.
Vidarbha 1st inngs: 583 for nine decl (S Badrinath 89, Ravi Jangid 83, Shrikant Wagh 81; Kamlesh Makvana 4/122).
Saurashtra 1st inngs: 20 for two in 17 overs (Shrikant Wagh 2/07).
