England were almost back on level terms with Australia after enjoying the better of the morning session on day three.
They wrapped up the last five wickets for just 48 runs, with Stuart Broad claiming a five-wicket haul, and two wickets apiece for James Anderson and Graeme Swann.
The session was overshadowed in some respects by the quality of the umpiring—Tony Hill in particular was culpable for a couple of poor decisions.
This time, fortunately, the DRS system was used to perfection and correctly overturned incorrect not out verdicts for both Chris Rogers (110) and Ryan Harris.
Harris ended the session on a high for Australia, however, with a jaffa of a ball to clean bowl Joe Root.
Afternoon session: England 123-3 (36 overs)
Another session of see-saw cricket saw the momentum swing Australia's way with Harris' super spell, and then back when Kevin Pietersen and Ian Bell combined to put on an unbroken stand worth 74 runs.
Harris drew an injudicious shot from Alastair Cook to end his innings on 22, while Jonathan Trott spurned another start and departed for 23.
At that point England's lead was just 17 runs with three wickets gone, but Pietersen and Bell's positive counter-punching knocks soon made England's position somewhat healthier.
Evening session: England 234-5 (74 overs) - Bell 105*
England took charge of the fourth Test after a strong batting performance led by man-of-the-series Ian Bell.
They finished the day at the Riverside on 234-5. leading by 202 runs with five second innings wickets intact.
In-form Warwickshire batsman Bell recorded his third century off the series off 184 balls with ten boundaries as his rich run of form continued.
He put on 106 for the fourth wicket with Kevin Pietersen before he fell for the second time in the match to spinner Nathan Lyon, a leading edge caught by Chris Rogers at cover after he had made 44.
Jonny Bairstow played with positive intent in making 28 before edging Lyon behind to keeper Brad Haddin late in the day.
In the context of a low scoring match, the hosts are now odds-on to take a 3-0 lead in the series.
England 2nd Innings
|Cook||c Haddin||b Harris||22||52||37||3||0|
|Trott||c Haddin||b Harris||23||33||29||3||0|
|Pietersen||c Rogers||b Lyon||44||152||84||6||0|
|Bairstow||c Haddin||b Lyon||28||82||65||6||0|
|Extras||0nb 0w 4b 2lb||6||Scorecard from BBC Sport|