England, who won the first test at Trent Bridge last Sunday by 14 runs, now lead Australia by 566 with six sessions still to play and fine weather forecast for the final two days.
Root, promoted to opener for the Ashes series after batting in the middle order against India and New Zealand, confirmed the class he has shown since scoring 73 on his Test debut last December.
His technique, poise and clean fluent driving on both sides of the wicket was of the highest order and marked him out as a worthy successor to his great Yorkshire predecessors Herbert Sutcliffe, Len Hutton, Geoff Boycott and Michael Vaughan.
Root reached his hundred with a cut to the point boundary and accelerated to pass 150 from 311 balls with 18 fours. He then struck two sixes over mid-wicket in leg-spinner Steve Smith’s final over the day.
Warner adds to woes
Troubled Australian batsman David Warner may have dashed his hopes of playing in the ongoing Ashes series after he failed in both innings of Australia A’s tour match against a Zimbabwe Select XI in Harare.
Warner was out for 11 against a modest home attack, after managing just six in his side’s first innings.