That happened in the NHL. I'm talking about international tournaments.
A lot of people are mentioning Henderson. He scored some very huge goals in that tournament but Esposito played better than him. Canada needed to win 3 games in Moscow. Esposito led Canada and without him I don't think they would win. Esposito's performance ranks right up there with Gretzky's and Lemieux's, if not higher.
Esposito put that Canadian team on his back in 1972. His speech after Game 4 in Vancouver really was the turning point in the series. Henderson scored the three straight game-winning goals, but Espo set the table.
Bobby Orr, on one leg in his final moment of glory, was magnificent in the 1976 Canada Cup. Rogie Vachon was Canada's 1A as far as MVP consideration.
A couple wingers who don't get enough recognition: John Tonelli in 1984 and Steve Larmer in 1991. Tonelli was the MVP of the 84 Canada Cup, and for good reason. He assisted on the overtime winner against the USSR in the semi-final, scored over a point-per-game, and was an all-round force. Larmer was very effective in the 1991 tournament. Coming off the best year of his career, he would have been a very reasonable choice as MVP. Need a goal? He'd score it. Check the opposing team's top forward? He'd do it. Win a battle in the corner? Larms got the job done.
As for the WJC, one performance stands above the rest: Manny Legace in 1992-93 in Sweden. Legace went from an obscure Quebec league goalie who'd be passed over in the draft twice, to a national hockey hero.
Canada was coming off an embarassing sixth place finish, and they had a young team that was expected to get a learning experience, in the hopes that they'd be ready to challenge for gold the following year. (Canada might have one or two undrafted players on their team most years. They had a lot that year). Legace was brilliant, especially during a 5-4 win over the heavily favoured host team, the Swedes.