Here's What Jimmy Fallon's Late Night Competition Had To Say About His 'Tonight Show' Debut

Jimmy Fallon's colleagues David Letterman, Jimmy Kimmel, Conan O'Brien, Craig Ferguson, and Seth Meyers were among the 11.3 million viewers who tuned in to watch Fallon take the reigns as host of "The Tonight Show" on Monday.

But Fallon's competition was fairly friendly when it came to their well-wishes and critiques of the premiere episode.

Jay Leno:

Prior to Monday's debut, Leno said of his "Tonight Show" successor: "I think he's probably the closest to Johnny [Carson] of anybody else in late night. When I watch him do, you know, a duet with Justin Timberlake or something of that nature I go, 'Well, I can't do that. I mean, I write jokes.'"

David Letterman:

During Monday's "Late Show" monologue, Letterman acknowledged the absence of his longtime late night rival, Jay Leno, by joking, "First thing this morning, I get a call from my mom. She says 'David, did something happen to Jay?' What am I gonna do?"

Letterman expressed his respect for Leno earlier this month when he said, "He was a host on 'The Tonight Show' for 22 years and now retiring. Congratulations on a wonderful run."

Craig Ferguson:

The CBS "Late Late Show" host joked during Monday's President's Day monologue that the former presidents live together in a clubhouse - as do all of the late-night hosts.

"I haven't seen Leno recently, though," Ferguson continued. "Although, one of his cars is still in the driveway, so maybe he's coming back."

When later discussing Bob Costas' return to host NBC's Olympics coverage, Ferguson joked, "I'm surprised NBC let him back. Usually when they replace a host, they stick with their decision" - referring to the Conan-Leno "Tonight Show" conflict of 2010.

Conan O'Brien:

Seth Meyers:

Seth Meyes and Conan O'Brien:

Jimmy Kimmel:

Daytime TV personalities weighed in:

There were celebrity fans:

And only a few haters: