UPDATE, 1:23 PM: The final tally is in and for last night’s XXX Summer Games (16.8/28) it was truly a Gold medal spike worthy of Beach Volleyball winners Kerri Walsh Jennings and Misty May-Treanor. With 29.1 million viewers on average tuning in, last night was the most watched second Wednesday of any Summer Olympics in 36 years. That includes the 1996 Atlanta Summer Games, which pulled in 28.9 million on its second Wednesday. While the London Games has often topped all other non-U.S. Summer Games since 1976, it has rarely done better than Games that were held in the United States. Of course, as it has in the final numbers for 12 of the 13 nights of the London Games, NBC’s primetime 8 – 11 PM coverage of the Olympics once again bested the 2008 Beijing Games. The Summer Olympics four years ago got 24.8 million on its second Wednesday, that’s 17% less than last night. Last night’s coverage was also up 11% in the ratings from Beijing’s 15.2/26 on the comparable night back in 2008. The 32.6 million viewers that NBC has had on average in primetime over the first 13 day s of the London Games is 3.6 million more than the average of 29.0 million that watched the first 13 nights of the Beijing Games.

PREVIOUS UPDATE: NBC released “fast official” ratings for the preview of Go On, which actually aired from 11:06-11:30 PM. It averaged a 5.6 rating in adults 18-49 and 16.1 million viewers and posted a 84% retention from the first to second half, according to NBC.

PREVIOUS: Last night’s Olympics coverage on NBC, punctuated by an all-American beach volleyball women’s final won by three-time champions Kerri Walsh Jennings and Misty May-Treanor, and a track & field gold rush, delivered a 9.2/27 among adults 18-49 from 8-11 PM and 28.7 million viewers in the fast nationals. That was up 14% from the same night during the Beijing games and down 5% from last Wednesday as Olympics ratings tend to taper off in Week 2. A commercial-free preview of NBC’s new comedy Go On starring Matthew Perry aired from 11:04-11:30 PM. NBC’s 11-11:30 PM fast national average was 18.6 million viewers and a 6.4/20 in 18-49. Extrapolating the numbers, Go On pulled in about 5.8 demo rating and 16.6 million viewers. While that is only a little more than half of the show’s lead-in (NBC’s Olympics coverage scored 10.4 and 30.6 million viewers from 10:30-11 PM), it is still good sampling for the new series. 

Elsewhere, Big Brother (1.8/6) was down 10% from last week to tie its series low while ABC’s Final Witness (0.8/2) was up 14%. Everything else was repeats.