Toulouse backs coach Jean Baptiste Elissalde admitted that he was not expecting his side to pick up all five points against Castres on Saturday.
Tries from Jean-Marc Doussain, Luke McAlister and Yacouba Camara saw Toulouse claim the maximum in a result that lifts them up to fourth.
McAlister added 11 points off the tee in a team performance that saw Gael Fickou and Clement Poitrenaud stand out at Stade Ernest Wallon.
"This is an unexpected result," said Elissalde.
"We hadn't counted on a bonus-point victory. We just wanted to continue to put a little more of everything in our rugby compared to the first six matches."
Toulouse travel to Perpignan next weekend in their final Top 14 game before the new Heineken Cup season begins with a home clash against Italian side Zebre.