One of the greatest Olympians of all time, US swimmer Michael Phelps, drew a large TV crowd for his final race. NBC’s Saturday night Olympic coverage, featuring Phelps’ last swim, posted a 16.4 overnight rating. That up +21% versus the prior Saturday night and up +.8 from the average for the games to date.

Not surprisingly, NBC’s Saturday coverage peaked at 20.4 overnight for Phelps’ final race, the 4x100m medley relay, from 10-10:15 PM ET, which the US won to bring Phelps’ overall haul to 23 Olympic gold medals and 28 total medals. The 31-year-old swimmer, who came back from retirement to compete in Rio, has ruled out — at least for now — a possible sixth Olympic run in Tokyo 2020.

In fast affiliates, last night’s 6.3/25 rating among adults 18-49 and viewership of 23.9 million was even in the demo with Friday – which means it matches the second lowest night of Rio 2016 in the key demo. As these entire Games have been, last night’s NBC packaged prime coverage was down from the comparable night of London 2012 by 27% in among the 18-49s and 16% in total viewers.

However, there is an upside in the early numbers in that the 2nd Saturday of the 2016 Games rose 23% in viewers and 15% in the demo from last week – which was the low of NBC’s Olympics coverage so far.

NBC Olympics coverage has topped 2 billion total streaming minutes via NBCOlympics.com & NBC Sports app.