Fox Television's broadcast of Super Bowl LI on Sunday night drew a 48.8 overnight rating, according to Nielsen data released by the network, lower than the previous two Super Bowls.
The contest included a thrilling finish, with the New England Patriots topping the Atlanta Falcons in the National Football league's first-ever Super Bowl overtime. The Patriots came back from a 25-point deficit and quarterback Tom Brady, 39, won his record fifth championship.
The brief overtime, in which the Patriots scored a touchdown in their first possession, allowed Fox to add four more commercials, and the network brought in an estimated $509.6 million in ad revenue for the broadcast, according to research firm iSpot.TV.
Last year's Super Bowl drew a 49.0 overnight rating, while the Patriots' previous title game appearance in 2015 helped Comcast Corp's NBC television draw a 49.7 rating, the highest overnight rating on record.
The overnight rating measures 56 major markets in the United States, representing about 70 percent of the country and is an early indication of what the final number will be.
Fox, a unit of 21st Century Fox, will have final numbers, including viewership, later on Monday.