Joe Root was in sight of a hundred as England maintained their vice-like grip on the second Test against Australia at Lord's.
England were 171 for four in their second innings, a lead of 404 runs, at tea on Saturday's third day.
Root was 97 not out and first innings centurion Ian Bell 16 not out.
The 22-year-old Root, playing his eighth Test, was preferred as England captain Alastair Cook's opening partner after making a maiden Test hundred as a middle-order batsman against New Zealand at his Headingley home ground in May, a match in which then opener Nick Compton struggled.
Together with Yorkshire colleague and England nightwatchman Tim Bresnan, Root put on 99 for the fourth wicket after a Peter Siddle treble strike Friday had left the hosts 30 for three.
Their partnership meant that by lunch Australia, shot out for just 128 on Friday, already needed to surpass the Lord's Test record fourth innings victory total of 344 for one made by the West Indies against England in 1984, which featured Gordon Greenidge's unbeaten double century, if they were to pull off an astounding win.
England, 1-0 up in the five-match series after last week's 14-run victory at Trent Bridge, resumed Saturday on 31 for three, a lead of 264 runs.
Root, 18 not out overnight, eased the first ball of Saturday's play, from Siddle, through midwicket for four.
After two days of blazing sunshine, conditions were overcast for the first time and offering a hint of swing.
Root, however, drove James Pattinson through the covers for four in a style reminiscent of former England captain Michael Vaughan, who played for the same Yorkshire club side as the Test novice.
