Resuming at 284, Sehwag was approaching the milestone in fine style but miscued a drive off Muralitharan, who fumbled once before taking the heart-breaking catch.
No player in the history of game has scored three triple centuries. Australian great Donald Bradman and legendary West Indies batsman Brian Lara are the only other players with two triple tons to their names.
Sehwag's triple hundreds came against South Africa (319 at Chennai in 2008) and Pakistan (309 at Multan in 2004).
The Indian opener also became only the fourth batsman in the Test history to fall in 290s.
New Zealander Martin Crowe was dismissed on 299 against Sri Lanka in 1991 while Sir Viv Richa
rds of the West Indies made 291 against England in 1976.
West Indies' Ramnaresh Sarwan was also dismissed on 291 against England in February this year.
Bradman had also managed an unbeaten 299 against South Africa in 1932.
Sehwag's scintillating 293 came off 254 balls with 40 shots to the fence and seven sixes at an amazing strike rate of 115.35.
Sehwag is the highest double century maker for India having a total of six such innings to his name, one more than Dravid. Tendulkar and Gavaskar have scored four double centuries each.
His other 200-plus scores are 254 against Pakistan (at Lahore in 2006), 201 not out against Sri Lanka (at Galle in 2008) and 201 against Pakistan (at Bangalore in 2005).
He has crossed the 150-run mark on 12 occasions.
The 31-year-old right hander has now scored 6248 runs from 72 matches with 17 centuries and 19 half-centuries at an impressive average of 52.50.
Most of the runs scored by Sehwag were made as opener, a position he first occupied at the Lord's Test against England in July 2002 after starting his Test career as a lower middle-order batsman at Bloemfontein against South Africa in November 2001.
