Indian batsman Karun Nair smashed an astounding triple century on Monday in just the third Test match of his career on day four of the fifth Test against England in Chennai.

The 25-year-old batsman started the day on 71 and notched his maiden Test century in the morning session.

But he wasn't going to settle for that and went on to reach 300 runs after the tea break as India took charge of the match by extending their first innings lead to well over 100.

He batted for 566 minutes in all, facing 381 balls, and hitting 32 fours as well as four sixes in his marathon innings.

Nair is the second Indian batsman to score a triple century in Test cricket, following in the footsteps of Virender Sehwag, who scored 319 runs against South Africa in 2008 at the same ground, as well as 309 runs against Pakistan in Multan in 2004.

Nair also became the highest individual scorer for India against England in Test cricket, going past Virat Kohli's 235 runs scored in Mumbai in the fourth test of this series.

It was also the highest score for an Indian batsman who scored his maiden test hundred. Nair went past Vinod Kambli's 224 runs against England in Mumbai (1993).

This was India's highest-ever test score, beating their previous best of 726 against Sri Lanka in 2009.

Post tea, first up, Nair crossed the 200-mark off 306 balls, as his 150-partnership with Ravichandran Ashwin (67) came up off 251 balls.

India's 600 came in the 168th over when England had taken the third new ball. The third new ball worked, as Ashwin was caught at gully by Jos Buttler off Stuart Broad.

But Nair, who had been dropped on 34 not out earlier, was again dropped on 217 not out by Joe Root at slip off Jake Ball (0-93) in the 172nd over.

Ravindra Jadeja (51) then put on 138 runs for the seventh wicket with Nair, the duo scoring at more than 7.2 per over.

Jadeja scored his fourth test half-century off 52 balls, including one four and two sixes, but it was Nair who attacked the bowling in pursuit of his landmark.

Nair went from 200 to 250 in the space of 42 balls, and then to 300 in 33 balls, hitting nine fours and three sixes in this interim. Jadeja, meanwhile, was caught at long-on off Liam Dawson (2-129).

After India declared with a sizeable lead, Alastair Cook (3 not out) and Keaton Jennings (9 not out) batted out five overs without any damage.