The ratings for the UFC's fourth effort on Fox are in and they paint a pretty similar picture to the last Fox show. Here's how the numbers break down by half hour (via TV By The Numbers):
8:00 - 0.9 Rating - 1.91 million viewers
8:30 - 1.1 Rating - 2.1 million viewers
9:00 - 1.2 Rating - 2.2 million viewers
9:30 - 1.2 Rating - 2.36 million viewers
For comparison, the third Fox card (headlined by Nate Diaz against Jim Miller) had 2.25 million viewers and a 1.0 rating in the overnight. That card was well behind the second Fox show, which took place in January which was behind the November single-fight debut on Fox.
The star power in last night's event was up from Diaz vs. Miller seeing as how there were two former world champions in the top two fights with Mauricio Rua and Lyoto Machida. Those fights look like they brought a small rise in viewership, but not a huge jump like we've seen in the past.
These ARE just overnight ratings, so a lot of adjusting could happen before the final numbers come out. For reference though, the 2.25 million viewers for Fox 3 had final numbers of an average of 2.4 million viewers.