Joe Root scored an imperious double century as England continued their strong start to the first Test against India on day two in Chennai.
England captain Root resumed on 128 and serenely compiled 218 to extend his stunning run of form.
His nine-hour epic helped England close on 555-8, Ben Stokes also making an enterprising 82.
The loss of four wickets in the evening session halted England's progress slightly but the tourists are still in an impressive position.
The pitch is offering increasing assistance to the spinners and seamer Ishant Sharma found notable reverse swing late in the day, which will please England's quick bowlers.
Root overcame all India threw at him until he fell lbw to left-arm spinner Shahbaz Nadeem in the evening session.
His score - the highest of any batsman in their 100th Test - is the best in India by an England player and the first double hundred by an overseas player in the country since 2010.
A weary India could have wrapped up the innings late in the day but for a horrible dropped catch by Rohit Sharma to reprieve Dom Bess, who ended 28 not out.