Briefly turning the tables and becoming the interviewer, Leno at one point got confrontational with Winfrey, alleging that her announcement last year that she would retire in 2011 was disingenuous.
"How many times are you going to retire?" he mockingly asked. "You and I will hold hands and walk out into the sunset together."
But Winfrey contended she meant what she said when she declared she would shut down "Oprah" after 25 years on the air.
As the interview wrapped up, she offered her own stance on O'Brien vs. Leno:
"I'm really surprised that so many people are against you, because I think people don't understand the way television works. I can understand people thinking you were selfish if you owned the show and controlled the show. It's a little surprising that people think that you stole the show, when it wasn't your show to steal."