At stumps, West were 314 for eight in 95 overs and have established a lead of 95 runs with captain Sairaj Bahutule (31) and Zheer Khan (8) at the crease to carry on the fighttomorrow.
Jaffer's record (for West in the tournament) sixth wicket stand with discarded Indian stumper Parthiv Patel (56) changed the course of their first innings after they were gasping at 79 for five.
Both batsmen showed responsibility and determination in ample measure in front of the watching selectors Kiran More, Pranob Roy and V B Chandrashekhar to pull West's fat out of the fire and place them in command.
Wicket keeper Parthiv Patel had done a good job behind the wicket yesterday and was responsible for three vital dismissals of South and continued his good show on the fieldwith the bat today.
He took 122 minutes in making 56 runs facing 79 balls, while Jaffer's 133 was studded with 15 fours and three sixes. he spent 298 minutes facing 197 deliveries at the crease.
The 145-run sixth wicket stand between Jaffer and Patel bettered the previous wicket mark of 127 standing in the name of Ravi Shashtri and Ramesh Borde.