According to Dave Meltzer of the Wrestling Observer, he reports:

The show did a 2.7 rating in prime time. The final rating will be higher because that number only counts 9-11 p.m. The peak half hour was a 4.7 for Kimbo Slice vs. James Thompson and that was after 11 p.m. Full ratings will be out on Tuesday but it's likely to be in the 3.0 to 3.1 range.

The overall number isn't through the roof but the growth was outstanding. It was No. 1 for the night in 18-34 and 18-49 as well as all male demos.

http://wrestlingobserver.com/wo/news/headlines/default.asp?aID=23023

It will be interesting to see the ratings on the next show. Hopefully this convinces the networks to give UFC a shot and show everyone what real MMA looks like.