Pagnis slammed 143 from 136 balls with 17 fours as Railways, put in, posted an intimidating 310 for six at the Mansarowar K L Saini stadium.
In reply, Vidarbha could muster only 251 for nine, their fight waning with the fall of Faiz Fazal and Alind Naidu.
Fazal hit a run a ball 52 and Naidu 72 off 69 balls and the duo saw Vidarbha rattle up 136 for one in 26 overs.
But three strikes by Shreyas Khanolkar turned the match on its head and paved the way for Railways' victory.
At the Sawai Mansingh stadium, Madhya Pradesh made Rajasthan's 298 for seven look inadequate as they successfully chased down the target with four wickets in hand and eight balls to spare.
Gagan Khoda laid the foundation for the hosts with 116 from 135 balls but the team lost direction midway while Shantanu Pitre returned an impressive 3-47, considering the domination of the bat in the match.
Amay Khurasia reminded his swashbuckling days with a 134-ball 157 studded with 19 fours and three sixes and provided the launch pad for the visitors' chase.