LOS ANGELES (Reuters) - Day nine of the Summer Olympics in Beijing, featuring swimmer Michael Phelps' historic gold-medal triumph, gave NBC its most watched Saturday prime-time broadcast in 18 years, the network said on Sunday.
The telecast averaged 31.1 million U.S. viewers, NBC's biggest audience for a Saturday night program since an episode of "The Golden Girls" spinoff "Empty Nest" drew 31.4 million viewers in February 1990, according to Nielsen Media Research data cited by the network.
Phelps was just 4 years old at the time, NBC said.
On Saturday, the 23-year-old pride of Baltimore, Maryland, helped the U.S. swim team to a first-place finish in the 400-meter medley relay in record time, giving Phelps the 14th gold medal of his career and his eighth at the Beijing Games.
The victory marked the most gold medals ever claimed by one athlete at a single Olympics, summer or winter, surpassing the previous record of seven golds won by swimmer Mark Spitz in 1972.
It was the culmination of an especially dramatic day of Olympic competition, which also saw Phelps' U.S. teammate Dara Torres, 41, lose the women's 50-meter freestyle by a 1/100th of a second to 24-year-old Britta Steffen of Germany. Torres, the oldest U.S. swimmer, ended up with three silver medals.
Jamaican sprinter Usain Bolt grabbed gold in the 100-meter dash after the reigning world champion Tyson Gay of the United States, who suffered a hamstring injury six weeks ago, was eliminated in the semi-finals.
But the dramatic story arc of Phelps, who came away with gold medals in all eight events he competed in, has been the biggest draw for NBC's Olympic coverage.
NBC Universal is a unit of General Electric Co.
The network has averaged 30 million viewers in prime time -- on par with the numbers tuning in for "American Idol" -- since the games opened on August 15, and Saturday night's audience peaked at 40 million viewers in the half hour during which the men's 400-meter medley was held.
Through nine days, 191 million viewers have tuned in to at least one six-minute bloc of the Beijing Games on NBC and its various sister cable networks -- 14 million more than for the Athens Games and 5 million more than the Atlanta Games over the same period, NBC said.