Joan Rivers made her Tonight Show debut with Johnny Carson on Feb. 17, 1965. Forty-nine years later to the day, Rivers appeared in the same NBC studio on the debut episode of The Tonight Show Starring Jimmy Fallon. In between, the highs of becoming Carson’s permanent guest host in 1983, and the lows of a “lifetime” ban from the show after Rivers bolted to host her own late-night talk show on FOX to compete with Carson; a ban that extended through the tenures of Carson, Jay Leno (twice), and even the short-lived Conan O’Brien months in the 11:35 p.m. hour on NBC.

Go figure.

Joan Rivers on The Tonight Show Starring Johnny Carson, April 25, 1986.

Joan Rivers on The Tonight Show Starring Johnny Carson, April 25, 1986.

Rivers, 80, made only a cameo on Fallon’s Tonight Show debut last month, but returned as a full guest on Thursday night’s episode, introduced by Fallon asking the audience to give her “a warm Tonight Show welcome” followed by The Roots playing Carson’s theme music to walk her onstage and over to the panel.

Fallon and Rivers danced around the topic of the actual reason for her feud with Carson — Fallon even overplayed the significance, welcoming Rivers “back to the network.” Rivers not only appeared on NBC’s Celebrity Apprentice but also trumped all of her competitors in the televised primetime contest in 2009.

joanrivers-johnnycarson-1965-tonightshow

Fallon held up a photo of Rivers with Carson on The Tonight Show in 1965. Rivers said that was from her second appearance on the program, and that was her big break as a stand-up comedian.

“I had been working for eight years in Greenwich Village and nothing. And he said, God bless him, ‘You’re going to be a star,'” Rivers said. “It changed my life.”

You want the inside story?

Be careful what you wish for. Instead of talking Carson, Rivers joked at length about her va-Joan-Joan.

Roll the clip!