The British pairing had been sitting in third after the first day, but moved up to second after another consistent evening of racing that saw them finish a lap ahead of previous leaders Kenny De Ketele and Moreno De Pauw.
Elia Viviani and Iljo Keisse also took a lap over the Belgians to finish the night in first place, just four points ahead of Wiggins and Cavendish.
It was another evening of racing dominated by the three pairings of Wiggins/Cavendish, De Ketele/De Pauw, and Viviani/Keisse, one of which took victory in all but two of the events.
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After the opening points races, elimination race, and time trial, the first real drama came in the first madison, where Viviani/Keisse finished a lap ahead of the field.
That move was almost cancelled in the final 30 minute plus six laps madison, where Wiggins and Cavendish were able to take a lap to draw themselves back into a close second place only four points off the lead.
It was a more difficult race for De Ketele and De Pauw, who finished a lap down and out of the points. However, the Belgian duo still lead in terms of points, so a lap taken tomorrow will be enough to see them regain the overall lead.