The batting heroics of the North Zone batsmen also helped their team take a 159-run lead after they had bowled out South Zone for 338 in the morning.
Gautam Gambhir (52, 4x6) also played a useful knock as he joined forces with Sehwag to put on 118 runs for the first wicket.
Sehwag despatched the ball in all directions to display his firepower and announce his intentions ahead of the Pakistan series. He hit 14 fours in his 57-ball 79.
However, South Zone got the much-needed breakthrough when Sehwag was caught by Robin Uthappa off Sunil Joshi in the 15th over with the total reading 118.
Yuvraj Singh carried on with his good form in the domestic circuit and reached his century in style with a six. His 110 also included 18 hits to the fence.
The Punjab batsman added 106 runs for the fourth wicket in company of Dinesh Mongia who made 47 (4x6).
Laxmipathy Balaji, who emerged as the most successful bowler of the day claiming five wickets, was however unable to check the run spree of the North batsman as tailenders Amit Mishra (60 not out, 4x11) and Amit Bhandari (64 not out, 4x4 6x4) had added 118 runs for the last wicket by close.
Earlier, resuming at their overnight score of 327 for nine, South Zone batsmen added 11 runs to the board before their innings folded up at 338 when Dinesh Kaarthick (59) was run out by Dinesh Mongia.