UFC Fight Night 66 took place on Saturday in Manila, Philippines and was headlined by former UFC lightweight champion Frankie Edgar scoring a decision win over former WEC featherweight champion Urijah Faber. 
According to Nielson sources, the main card broadcast on Fox Sports 1 had an average live audience of 575,000 viewers and the preliminary card drew 246,000 viewers.
When it comes to the peak of the broadcast, it came during the 1:15 p.m -1:30 p.m. ET quarter hour with 718,000 viewers.
The replay of the card was show on Fox Sports 2 on Saturday night at 9 p.m. ET and drew an additional 155,000 viewers.
The top sports program on Saturday was the NASCAR Sprint Cup All-Star Race on Fox Sports 1 with 3.8 million viewers. Other top sports programs included boxing on HBO, NCAA softball regionals on ESPN, and MLB baseball on Fox Sports 1.
With the viewership from NASCAR, UFC, and MLB on Saturday, Fox Sports 1 was the number one ad-supported sports cable network and the average viewership numbers for UFC Fight Night cards in 2015 is below.
UFC Fight Night 59: 2.75 Million (Prelims – 908k)
UFC Fight Night 60: 913k (Prelims – 775k)
UFC Fight Night 61: 1.2 Million (Prelims – 813k)
UFC Fight Night 62: 617k (Prelims – 280k) *
UFC Fight Night 63: 389k (Prelims – 304k)
UFC Fight Night 66: 575k (Prelims – 246k)
* – Prelims aired on Fox Sports 2.