According to preliminary Nielsen ratings, NBC's "Late Night with Jimmy Fallon" beat CBS' "Late Late Show with Craig Ferguson" by a 35 percent margin in their first head-to-head clash Monday. The inevitable curiosity about Fallon's first night helped the show post a one-third boost over the average ratings performance by Monday airings of "Late Night" so far this season.

Taking over as host from Conan O'Brien, Fallon had Robert De Niro, Justin Timberlake and Van Morrison as guests on his first show. Fallon, decked out in a black suit and looking terminally clean-cut, opened with a fairly traditional monologue that drew too few laughs, followed by a couple of prepared bits that were long on ambition but failed to connect. He just tried to hard to make the best impression ever.

His interview with Robert DeNiro was a fiasco. DeNiro's a bad guest under ordinary circumstances, but by opening with the list of questions with one-word answers, as opposed to saving it for a moment when the interview went south, Fallon essentially told DeNiro to phone it in.

But definitely the shining moment of “Late Night with Jimmy Fallon” was Justin Timberlake's appearance. Fallon seemed truly thrilled to see his “Saturday Night Live” sketch-pal, and laughed with genuine, grateful appreciation when Timberlake busted out excellent John Mayer and Michael McDonald impersonations.

Van Morrison came out and rumbled through an “Astral Weeks” number and Fallon rattled off the week's upcoming guests, who will include Tina Fey and Cameron Diaz.