Matthew Wade continued to assist Smith after the dismissal of Head in the first session and the two went on to put up 126 runs for the fifth wicket as Australia's lead ballooned to 266 runs at Tea. Smith was finally dismissed for 142 as Australia ended the second session of Day 4 at 357/5.
Wade was unbeaten on 86 when umpires called for Tea with captain Tim Paine at the other end. Australia will look to make quick runs in the third session and declare so that they stand a chance of winning the match.
Chris Woakes, who curiously enough did not bowl for the entirety of the first session, was the man who got the wicket of Smith. England took the new ball after the 84th over with Broad bowling the 85th. Smith got off strike off the first ball and then came back only to face Woakes in the next over.
The first delivery was a widish one outside off which swung in late as Smith nicked it to Jonny Bairstow behind the stumps.
Smith became the first Australian batsman to notch up tons in both innings of an Ashes Test after Matthew Hayden in 2002, and the fourth Australian overall to achieve the feat in Ashes.
It was also Smith's 10th Ashes century and only England's Jack Hobbs (12) and Australian legend Sir Donald Bradman (19) have scored more centuries in the keenly-contested rubber.
Brief scores: 1st innings: Australia 284 all out (Steve Smith 144, Broad 5/86); England 374 all out (Rory Burns 133, Nathan Lyon 3/112); 2nd innings: Australia 231/4 (Steve Smith 144, Mathew Wade 86 not out, Ben Stokes 2/49)
( With inputs from IANS )