• by David Goetzl  @dgoetzl, March 2, 2010

All the tumult NBC went through as it reinstalled Jay Leno as host of "The Tonight Show" may have been worth it. Leno's return Monday crushed the "Late Show with David Letterman" and posted stronger numbers than Leno's average before he ceded "The Tonight Show" role.

Leno's comeback drew 6.6 million viewers and earned a 1.6 rating in the adult 18-to-49 demo. On CBS, Letterman had a respective 3.8 million and a 1.1 in the "live plus same day" returns.

Leno's viewer numbers Monday were 26% higher than his average for the 2008-09 season -- his apparent last on NBC in late night -- and 46% above his 18-to-49 performance.

Monday's "Tonight Show," however, likely benefited from heavy promotion during the Olympics and perhaps from skiing gold medalist Lindsey Vonn as a guest. Also helpful was a presumed curiosity factor about whether the show felt the same as when Leno was last behind the desk -- and what type of opening comments he would offer.

Still, even if ratings drop, as would be expected, Leno looks to be on track to easily top what Conan O'Brien was doing as "Tonight Show" host. Leno's Monday viewership was 144% above what O'Brien was averaging this season, and 45% higher in the 18-to-49 demo -- which was a relative strength for O'Brien.

Letterman's 4.2 million average viewership this season was besting O'Brien's by 1.5 million. O'Brien, however, was on top slightly in the 18-to-49 demo with a 1.1 versus "Late Night's" 1.0.