In the opening match of the Student Rugby League Europa Cup, Tartarstan beat Ireland 38-12 with loose forward Robert Ilyasov taking the man-of-the-match award.
Players and officials from the home nations were stunned when a crowd of 16,000 turned up in the old Soviet city of Kazan to watch the match.
Mark Dando, captain of the Welsh students, said: "This is absolutely unbelievable. It's beyond belief, it's like being in the Olympics. This is something that I will never, ever forget.
"Rugby league is absolutely colossal out here. We've got as many people here as there are at Premiership games".
Neil Wood, director of Student Rugby League, said: "The people of Tartarstan have demonstrated that they care about their state and about the sport of rugby league.
"Rugby league is a family sport and today we have welcomed a new child to the sport and I expect that that child will grow into a very healthy adult".