Ravichandran Ashwin, who has enhanced his reputation with the bat by hitting three half-centuries in the series, was batting on nine at the other end.
Nair's knock was not a flawless one but the 25-year-old hung on to help India, who have already wrapped up the series with a match to spare, reduce the deficit with some stolid batting in the 72-run morning session.
Dropped on 34 by Alastair Cook on Sunday, Nair enjoyed another slice of luck when he hung out his bat trying to leave a short Stuart Broad delivery, the deflection running past slip to the boundary.
He looked more in control when he stepped out to hit debutant Liam Dawson for six and reached triple figures by slicing Ben Stokes for a boundary.
Murali Vijay was lucky not to be given caught behind to Broad, who celebrated the 'dismissal', after UltraEdge technology showed a faint nick, but England had used up their reviews and could not challenge the decision.
Vijay was unable to truly capitalise on the reprieve, however, as he became Lawson's first test victim.
