The aggressive running style which harvested 149 tries in 152 appearances in five-and-a-half years at the Bulls quickly acclimatised to the 15-man code in the most auspicious manner possible.
The 28-year-old, whose explosive finishing power has earned him the nickname Volcano, said: "I didn't think I was going to get that many tries.
"I was just going out there and concentrating on the way I want to play."
He added: "Credit to my team as well - the forwards did the hard yards and the backs finished."
Leeds coach Stuart Lancaster was full of praise for the debutant, saying: "I've seen Lesley Vainikolo do that to world-class defences and he did to us again today.
"To make an impact like this in his first game of rugby union is very, very impressive.
"All credit to him and Gloucester for creating and taking those opportunities.
"They played well but we competed well across the park and have got lessons to learn and lots of positives to take as well."