UPDATE: Final national numbers released by Nielsen this afternoon show Tuesday’s primetime Olympics averaging a 12.8 rating/35 share in adults 18-49, the best for any night of the London Games, and 38.72 million viewers overall, second only to the Opening Ceremonies.

The 38.7 million viewers is the most for the first Tuesday of any non-U.S. Summer Olympics in the history of televised Games (since 1960). And through the first five nights, this year’s Olympics are averaging 35.6 million viewers — 4.3 million more than Beijing and the most for any non-U.S. Summer Olympics since Montreal in 1976.

NBC’s coverage of a great night for Team USA — highlighted by Michael Phelps’ record-setting performance and a gold-medal finish for the women’s gymnastics team — drew gaudy numbers Tuesday night.

Nielsen estimates that from 8 to 11 p.m., NBC averaged a 12.2 rating/33 share in adults 18-49 and 37.5 million viewers overall, with the demo score matching that of the Opening Ceremonies on Friday and the total viewer count the best since that night. The Olympics remain a broad draw, scoring well in demos ranging from teens (7.0/25) and men 18-34 (8.7/30) to its strongest key demo category, women 25-54 (15.6/35).

Tuesday’s performance was on par with the comparable night in Beijing four years ago as NBC remains ahead of its ratings pace through five of 17 nights from London.

Elsewhere, Univision’s original novelas ran second among young adults, led by the strong ”La Que No Podia Amar” (The One Who Couldn’t Love), which averaged a 1.7/4 in 18-49 and 4.3 million viewers overall in the 10 o’clock hour.

There was very little happening at other broadcasters Tuesday, as most nets aired repeats.

CBS went with encores of ”NCIS” (1.0/3 in 18-49, 6.8 million viewers overall), ”NCIS: Los Angeles” (1.0/2 in 18-49, 5.2 million viewers overall) and ”Person of Interest” (0.9/2 in 18-49, 4.4 million viewers overall) and Fox aired repeats of ”MasterChef” at both 8 (1.0/3 in 18-49, 2.3 million viewers overall) and 9 (0.9/2 in 18-49, 2.1 million viewers overall).

ABC’s lone original, ”NY Med” at 10 p.m., settled for a 0.6/1 in 18-49 and 2.8 million viewers overall. Earlier, the net aired repeats of ”The Middle” (0.7/2 in 18-49, 2.8 million viewers overall), ”Last Man Standing” (0.5/2 in 18-49, 2.2 million viewers overall) and ”Wipeout” (0.7/2 in 18-49, 2.4 million viewers overall).

CW’s original airing of ”The L.A. Complex” at 9 p.m. maintained its 0.2 rating in both 18-49 and 18-34 while bulking up some in total viewers (to 550,000). At 8, an encore of ”Hart of Dixie” also did a 0.2 demo rating and drew about 800,000 viewers overall.

Preliminary 18-49 averages for the night: NBC, 12.2/33; Univision, 1.4/4; CBS, 1.0/3; Fox, 0.9/3; ABC, 0.6/2; CW, 0.2/1.

In total viewers: NBC, 37.5 million; CBS, 5.4 million; Univision, 3.5 million; ABC, 2.6 million; Fox, 2.3 million; CW, 0.7 million.