Dutchman Theo Bos won his first senior sprint title yesterday with a commanding 2-0 performance over Rousseau's compatriot and defending champion Laurent Gane.
The last ride of the championships ended the week perfectly for the host nation, as Australian Ryan Bayley came back from 1-0 down to beat Pole Damian Zielinski 2-1.
Bos is only 20 and Bayley, the 2001 world keirin champion, is 22.
Bos, who beat Bayley 2-1 earlier in their semi-final, showed great mental strength yesterday.
He crashed twice in Saturday night's quarter-final win against British rider Jamie Staff.
"I could barely walk, so I started riding and it was okay, but walking was (still) painful in my back," he said.