Fast National ratings for Monday, July 7, 2014.

CBS' "Under the Dome" plummeted nearly 20 percent to a series low in the season's second week, still leading Monday overall, but falling behind a slew of Monday originals in the key demo as FOX eked out wins in all measures.

"MasterChef," "The Bachelorette" and "American Ninja Warrior" all topped "Under the Dome" with young viewers, while "The Bachelorette" closed the gap on "Under the Dome" overall.

Among other Monday notables, the "Beauty and the Beast" season finale got a small overall bump, as did FOX's "24: Live Another Day." ABC's "Mistresses" was down week-to-week.

On to the numbers...

Among adults 18-49, FOX averaged a 1.7 rating for Monday primetime, beating ABC and NBC's 1.5 rating in the key demographic. CBS was fourth with a 1.3 key demo rating, while The CW did a 0.4 key demo rating for Monday.

Overall, things were even closer. FOX averaged 5.85 million viewers for Monday night along with a 3.5 rating/6 share. With a 3.9/7, ABC had the night's best rating and share, but finished second with 5.8 million viewers, followed closely by the 5.78 million viewers and 3.6/6 for CBS. NBC wasn't that far off with a 2.9/5 and 4.92 million viewers. The CW averaged 1.17 million viewers and a 0.7/1 for Monday.

8 p.m. - "The Bachelorette" started primetime in first overall with 6.74 million viewers and finished a close second with a 1.8 rating among adults 18-49 for ABC in the 8 p.m. hour. FOX's "MasterChef" got an overall bump to 5.7 million viewers and was steady week-to-week with an hour-winning 1.9 rating among adults 18-49. CBS' repeats of "2 Broke Girls" and "Mom" finished third with 4.63 million viewers and a 1.1 key demo rating, edging out the 4.04 million viewers and 1.0 key demo rating for NBC's "Last Comic Standing" clip show. The CW's two "Whose Line Is It Anyway?" repeat averaged 1.47 million viewers and a 0.5 key demo rating. 

9 p.m. - ABC remained in first overall for the 9 p.m. hour with 6.93 million viewers for "The Bachelorette," which also moved into first with a 1.8 rating among adults 18-49. FOX's "24: Live Another Day" averaged nearly 6 million viewers for second and a 1.5 key demo rating for third in its penultimate airing. NBC's "American Ninja Warrior" averaged 5.16 million viewers for third and a 1.7 key demo rating for second. CBS' repeats of "Two and a Half Men" and "Mike & Molly" finished a close fourth with 4.99 million viewers and a distant fourth with a 1.1 key demo rating. The season final for "Beauty and the Beast" averaged 876,000 viewers and a 0.3 key demo rating for The CW.

10 p.m. - "Under the Dome" won the 10 p.m. hour overall for CBS with 7.71 million viewers, but finished second with a 1.7 rating among adults 18-49. NBC's "American Ninja Warrior" won the hour in the key demo with a 1.9 rating and finished second with 5.55 million viewers. ABC's "Mistresses" trailed with 3.75 million viewers and a 0.9 key demo rating.

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