Britain's Sir Bradley Wiggins and Mark Cavendish took the lead at the Ghent Six Day after dominating day four.
Starting in third place, the pair won the team elimination race and then the day's first madison, with Wiggins claiming victory in the derny final.
The teams of Kenny De Ketele / Moreno De Pauw and Elia Viviani / Iljo Keisse are only one lap down and both have more points than the leading pair.
Wiggins, 36, has hinted the race in the city of his birth could be his last.
After finishing second to De Pauw and De Ketele of Belgium in last month's Six Day London event, the five-time Olympic champion said he could be tempted to race there again next year.
But on Monday he told reporters to ask him on Sunday, at the end of the Ghent event, whether this would be his last race.