"With the all the controversy going on here at NBC, actually, The Tonight Show with Conan O'Brien's ratings have gone up. They've gone up. So you're welcome!" Leno exclaimed his monologue.
The latest jibes came as The Daily Beast reported that O'Brien and the network were close to a deal in which he'd receive a payout and be free to appear on another network before his contract expires.
"In other TV news ... Sarah Palin has signed with Fox News to be a correspondent. In a statement today, Fox said if Miss Palin does a good job, they'll sign her to a long-term contract. If she doesn't work out, they'll just blame Leno," the host of The Jay Leno Show said.
And Leno had Jimmy Kimmel on as a guest to ask: "What is the secret to doing a good Jay Leno impression?"
Watch Kimmel's answer:
Later on Jimmy Kimmel Live! he recalled how NBC once had a long reign as the No. 1 broadcast network. "They had Cosby and Seinfeld and Cheers — great shows. And now they're in last place and — a mess. It's like going to your high school reunion and the homecoming king went bald and works in a lawnmower repair shop."
For his part, O'Brien later joked about a porn film company offering him a role. "In the movie I'd be having sex with a beautiful woman and just as we're about to climax, I get replaced by Jay Leno," he said.
"No matter what happens," he went on, "it's been a real honor to sit in the same chair as Steve Allen, Jack Paar, Johnny Carson, Jay Leno — and Jay Leno."
The latest verbal onslaughts came amid reports that Leno would get back an hourlong Tonight at 11:35 — if O'Brien stuck to his refusal to move to a half-hour later with the franchise. An NBC rep said there was no deal, however.
"Our good friend Ricky Gervais will be hosting the Golden Globes, if Jay lets him," he said.
Letterman explicitly noted that "Jay is getting a lot of negative publicity," then showed a mock campaign-style commercial supposedly released by Leno. The spot says Leno "represents traditional American values ... like killing Indians because you want their land."
Check it out: