The Nielsen Co. said that the seventh game victory was seen by about 8.5 million people on NBC last week. A winner-take-all game between a Boston team that hadn't won professional hockey's championship in 39 years against a team that had never won proved to be a real draw.
It was the biggest audience since a 1973 playoff contest between Montreal and Chicago.
Sports on TV have been attracting bigger audiences in recent years with the rapid expansion of high-definition television and large-screen sets.
The game and talent competitions enabled NBC to win the weekly ratings race for the first time since New Year's week.