Smith (215) and Chris Rogers (173) were parted at last, by the impressive Stuart Broad - but not before they had posted Australia’s highest stand at the home of cricket, 284 for the second wicket.
James Anderson insisted the previous evening that England merely needed to ‘win’ the remaining four days to go 2-0 up.
He and Broad strived to make good on that intention. But Smith refused to yield until almost tea as Australia extended their plunder on this most benign of pitches.
He lost his status as the world’s number one batsman when he mustered only two 33s in last week’s defeat at Cardiff, but will surely be heading back to the top after passing 200 for the first time at any level - and becoming only the third Australian to do so at Lord’s.
The moment came in mid-afternoon with a clip past midwicket off Moeen Ali for Smith’s 24th four from the 336th ball he had faced.
England’s rewards for their improved bowling efforts were relatively meagre before lunch.
They amounted to Rogers’ departure, after more than six-and-a-half hours and 300 balls, and then Michael Clarke’s too following a much shorter and more vexed stay.
Rogers drove at the pitch of a Broad inswinger and inside-edged on to his stumps via pad too.
Clarke appeared to have nowhere to go when England went short at him - and having struggled to seven off 32 balls, the Australia captain mistimed a pull straight to square-leg off Mark Wood.
But it was in early afternoon that England, thanks to Broad (three for 79), had a sudden and temporary spike of progress.
One very good delivery appeared to be slanting up the slope on the angle, but then nipped down it to take a thin edge and have Adam Voges caught-behind.
Mitchell Marsh drove his first ball from Broad past mid-off for four but was soon undone when he went back to one that did not make the expected height, and induced the chop-on.
If England thought the damage limitation was under way, though, debutant wicketkeeper Peter Nevill had other ideas in a stand of 91 with Smith which ended only when the senior partner was finally dismissed - lbw chancing a reverse-sweep at part-time off-spinner Joe Root.
After a DRS process which marginally endorsed the decision, he departed to a universal standing ovation from Lord’s full house - the level of non-partisan acclaim reserved for a truly memorable performance.
Root doubled up with the wicket of Nevill, driving low to mid-off, before inviting England’s reply after Mitchell Johnson holed out off Broad one over into the evening session.