Plymouth Albion scrum-half Tom Kessell scored the opening try as England Counties beat The Rock 20-6 in the first game of their Canadian tour.
Winger Fergus Mulchrone and flanker Will Fraser also appeared on the scoresheet for England as they proved too powerful for their opponents.
The remainder of England's points came from Ross Winney, while Dean Banks kicked two penalties for The Rock.
The second game of the tour is against Ontario Blues in Toronto on Tuesday.
Manager Danny Hodgson said his side excelled themselves in the win over The Rock.
He said: "Our discipline was superb, conditions were difficult and we were confronted by a big, physical side, but we played to the conditions and I'm very pleased.
"The game and the opposition was exactly what we expected and we came through.
"It's so important to win your first game and when that win comes against a proper team, the success is so much more valuable."