England conceded their highest Test score to any opposition as triple-centurion Karun Nair piled on the agony for Alastair Cook's tourists in India's own national-record 7(dec)-759.
Nair (303 not out) became only the third batsman in history to turn a maiden century into a triple, following Sir Garfield Sobers and Bobby Simpson, as England's previous-worst of 5-751 against West Indies in Antigua in 2004 was consigned to history.
Nair, in only his third Test after previous scores of four and 13, shared a sixth-wicket stand of 181 with Ravi Ashwin (67) on day four of this fifth Test to help India rack up a mammoth lead of 282 at the MA Chidambaram Stadium.
Virat Kohli declared immediately after Nair cut Adil Rashid for his 32nd four, to add to four sixes, and reach his triple-hundred from 381 balls in almost nine-and-a-half hours.
That put the onus on England's batsmen to summon a resilience often previously lacking on this tough tour if they are to avoid going home 4-0 losers, by closing out a stalemate over the remainder of Monday and on the final day.
