The first presidential debate between John McCain and Barack Obama drew a sizable aud on Friday, topping two of the three such get-togethers from 2004.

According to Nielsen estimates, an average aud of 52.42 million watched live from 9 to roughly 10:40 p.m. ET on ABC, CBS, Fox, NBC, Telefutura, Telemundo, BBC-America, CNBC, CNN, Fox News Channel and MSNBC. (PBS, not tracked by Nielsen, estimates it drew 2.6 million.)

This was down from the first debate four years ago (62.5 million for George Bush and John Kerry) but it topped the only Friday presidential debate of that year (46.7 million). By comparison, the final nights of both the Democratic and Republican conventions a month ago (airing on Thursdays) drew between 38 and 39 million viewers.

Nielsen did not break out individual broadcast network tallies because the event ran “sustained” (without commercials). In cable results, however, Fox News led the way (8.21 million), followed by CNN (7.14m) and MSNBC (3.92).

The first vice-presidential debate is set for Thursday night, with two more prexy debates on tap for Oct. 7 and 15.

— Rick Kissell