Fast National ratings for Wednesday, May 21, 2015.

CBS cruised to victory on the last night of the 2014-15 season with three hours of "Survivor: Worlds Apart" finale coverage, which swept primetime in most measures. 

NBC finished second overall thanks to strong performances from finales for "The Mysteries of Laura," "Law & Order: Special Victims Unit" and "Chicago PD," while a series low finale for "Modern Family" still put ABC in second in the key demo.

There were a couple summer premieres on Wednesday, with ABC's "500 Questions" having an OK series launch and FOX's "MasterChef" premiere coming in a bit soft, though both shows did the same 18-49 rating.

Let's get to the numbers...

Among adults 18-49, CBS averaged a 2.1 rating for Wednesday night, tops in the key demographic. ABC was second with a 1.4 key demo rating, followed closely by NBC's 1.3 key demo rating and the 1.2 key demo rating for FOX. The CW averaged a 0.5 key demo rating for Wednesday night.

Overall, CBS averaged an estimated 8.99 million viewers and a 5.3 rating/9 share for Wednesday night. NBC was second with 7.23 million viewers and a 4.8/8, far ahead of ABC's 4.87 million viewers and 3.2/6. FOX's 3.335 million viewers and 2.1/4 finished fourth, followed by The CW's 0.9/2 and 1.43 million viewers for Wednesday night.

8 p.m. - The first hour of the 'Survivor: Worlds Apart" finale averaged 9.45 million viewers and a 2.1 rating among adults 18-49 for CBS. NBC's "The Mysteries of Laura" was second with 7.26 million viewers and fourth with a 1.1 key demo rating. ABC's "500 Questions" averaged 5.03 million viewers to top the 3.305 million viewers for FOX's "MasterChef," which both hours averaged a 1.2 key demo rating for second. A "Supernatural" encore averaged 1.07 million viewers and a 0.3 key demo rating for The CW.

9 p.m. - "Survivor" rose to 10.04 million viewers and a 2.3 rating among adults 18-49 to lead CBS in the 9 p.m. hour. "Law & Order: Special Victims Unit" was second with 7.235 million viewers and third with a 1.4 key demo rating for NBC. ABC was third overall and second in the key demo with "Modern Family" (7.11 million and a 2.2 key demo) and "Black-ish" (5.39 million and a 1.6 key demo). FOX's "MasterChef" averaged 3.365 million viewers and a 1.2 key demo rating for fourth. The season finale for "Supernatural" averaged 1.78 million viewers and a 0.7 key demo rating for The CW.

10 p.m. - The conclusion of "Survivor: Worlds Apart" and the subsequent live post-show averaged 7.48 million viewers and a 1.8 rating among adults 18-49 for CBS. NBC's "Chicago PD" finale was second with 7.19 million viewers and a 1.4 key demo rating. ABC's "Celebrity Wife Swap" finale averaged 3.33 million viewers and a 1.0 key demo rating in the 10 p.m. hour.

All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.

A long-time member of the TCA Board and a longer-time blogger of "American Idol," Dan Fienberg writes about TV, except for when he writes about movies or sometimes writes about the Red Sox. But never music. He would sound stupid talking about music.