Left-arm orthodox spinner R Sai Kishore's maiden match haul of 10 wickets ensured a staggering 645-run victory for South Zone over North to set up a clash with West Zone in the Duleep Trophy final starting on Wednesday.
The margin of victory was one of the highest in Indian first-class cricket.
West Zone also won their semi-final in commanding fashion beating Central Zone by a comfortable 279-run margin. The final will be played in Coimbatore from September 21, and it will be a five-day affair.
In the South versus North game, the contest was killed by the winning team's batters when they piled up a mammoth 630/8 declared in their first innings, riding on hundreds from opener Rohan Kunnummal, skipper Hanuma Vihari and Ricky Bhui.
Once North were all out for 207 in their first innings, courtesy Sai Kishore's 7/70, the writing was on the cards.
South didn't enforce follow-on and scored 316/4, piling on North's misery by giving them an improbable target of 740 to chase.
On the final day, North were bowled out for 94 in 30.4 overs with Sai Kishore (3/28), off-spinner Krishnappa Gautham (3/50) and another slow left-armer, Tanay Thyagarajan (3/12), sharing the spoils.
It was a match that belonged to Sai Kishore for his stupendous effort (10/98 in 39 overs) as the pitch wasn't difficult to bat on.
Sai Kishore varied his pace and lengths to trouble the North batters with only opener Yash Dhull (59 off 58 balls) showing some counter-attacking instincts.
The innings was terminated at the fall of ninth wicket as Navdeep Saini, who has been declared unfit by the BCCI, didn't come out to bat.
As many as eight North batters failed to reach double figures.
Mulani takes five-for
Left-arm spinner Shams Mulani, who finished as the highest wicket-taker in Ranji Trophy, continued his rich vein of form by taking 5 for 72, as West made short work of Central in the other semifinal.
Chasing a gigantic target of 501, Central were never in contention to make a match of it and were all out for 221 in little over 57 overs.
Chintan Gaja, the seamer whose mindless bravado of deliberately throwing the ball back on follow through injured Venkatesh Iyer, also got his act together and chipped in with three wickets.
Rinku Singh (65 off 71 balls), and 'concussion substitute' Ashok Menaria (in place of Venkatesh Iyer) (32 off 71 balls), delayed the inevitable with a 87-run stand for the seventh wicket.
Starting the day at 33/2, the question was how long could Central Zone hang on. West had virtually sealed it after their opponents were all out for 128 in reply to the winner's 257 in the first essay.
Prithvi Shaw was deservingly named the Player of the Match for his 60 and 142 in the two innings.
It was his offensive approach at the top of the order in both the innings that put Central on the back-foot.
South Zone 630/8 decl & 316/4 decl.
North Zone 207 & (target 740) 94 all out in 30.4 overs (Yash Dhull 59, R Sai Kishore 3/28, K Gowtham 3/50, Tanay Thayagrajan 3/12).
SZ won by 645 runs.
West Zone 257 and 371.
Central Zone 128 and (target 501) 221 in 57.1 overs (Rinku Singh 65, Shams Mulani 5/72).
West Zone by 279 runs.