A new era in latenight television commenced on Monday, with NBC's "Tonight Show Starring Jimmy Fallon" easily keeping the venerable program on top of the ratings heap.

Taking advantage of NBC's dominance in primetime courtesy of its coverage of the Winter Olympics -- and starting 30 minutes later than usual because of it -- Fallon's debut as host averaged a 7.1 overnight household rating/20 share, according to Nielsen. This put it about 80% higher than the combined overnight Monday rating for the programs hosted by Jimmy Kimmel on ABC and David Letterman on CBS.

Coincidentally, the 7.1 is the same overnight score that NBC saw for its post-Jay Leno "Tonight Show" host the first time, as Conan O'Brien premiered to that rating in June 2009.

While no one expected Fallon to approach the huge 9.2/22 that Jay Leno logged with his recent "Tonight" swansong (at the more advantageous start time of 11:35 p.m.), Monday's premiere-night rating is well above the previous high for Fallon as host of "Late Night" (4.8/13) and is slightly more than double what Leno averaged in his penultimate week of Jan. 27-31 (3.5/9). The season-to-date average in the metered-market overnight rating for "Tonight" is 2.9.

That 4.8 "Late Night" overnight rating for Fallon translated to about 6.6 million viewers in the nationals, so something in the vicinity of 9 million to 10 million viewers is likely for his "Tonight Show" premiere. Preliminary total-viewer estimates are expected to be issued later today by Nielsen.

In the 25 markets with Local People Meters, the premiere of "The Tonight Show Starring Jimmy Fallon" averaged a 3.4/17 in adults 18-49 -- the highest ever for a Fallon-hosted latenight program and 62% bigger than the 2.1/10 for the Friday, Feb. 7 finale of "Late Night With Jimmy Fallon."

Monday's premiere, featuring Will Smith, U2 and celebrity cameos including Stephen Colbert, Robert De Niro and Tina Fey, marked the return of "The Tonight Show" to New York City, where it originated in 1954.

"Tonight" has been the No. 1-rated latenight program for most of the time it's been on the air for NBC, from Jack Paar and Johnny Carson through the two stints of Leno. But with the passing of the baton from Leno to Fallon, both ABC (with Kimmel) and CBS (with Letterman) see an opportunity to gain competitive ground.

In a bid to provide as much support as possible for their latenight programs, ABC and CBS aired original dramas in the 10 o'clock hour on Monday (unusual for both to do so during the Olympics), but they were overwhelmed by the Sochi Games. The Olympics on NBC averaged a 14.6 overnight household rating/22 share in primetime on Monday -- besting the combined tallies for ABC, CBS and Fox (12.7/19) and the highest since the opening Sunday (Feb. 9).

NBC has now effectively used its primetime ratings advantage during the Olympics to both send off Jay Leno and usher in Fallon as host of "The Tonight Show."

The final night of "Tonight" for Leno, which aired Feb. 6, averaged a big 3.8 rating/16 share in adults 18-49 and 14.64 million viewers overall in Nielsen nationals. This made it the show's largest overall audience in more than 15 years (since the night of the May 1998 series finale of "Seinfeld"), and was Leno's top demo score since an appearance by President Obama in March 2009.

Fallon wrapped its run as host of "Late Night" one day later with a 2.1/10 in 18-49 and 6.6 million viewers overall in the nationals -- the largest audience for the franchise since the June 1993 finale of "Late Night With David Letterman." In the demo, it was Fallon's second-best telecast ever, behind only a 2.5 rating for a special post-Super Bowl telecast in 2012, and the best for a regularly scheduled installment of "Late Night" since May 2004 (2.7), on the night of the "Friends" finale.

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