Gayle King Reacts to Oprah's Interview with Lance

ET's Rocsi Diaz chatted with Oprah Winfrey's best friend Gayle King on Sunday, where the CBS This Morning co-anchor revealed that Lance Armstrong wasn't the only one with a lot at stake during last week's interview.

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"I've only seen [Oprah] nervous twice -- Michael Jackson, back in the day that was live, and with Lance Armstrong," Gayle said at The Daily Beast/Newsweek bipartisan brunch. "She knew that there was a lot at stake. She knew that people would be watching her and she knew that people would be watching him."

Those nerves may have brought out the best in Lady O, as Gayle revealed Oprah's preparation leading up to the sit down. Gayle told Rocsi that Oprah looked at every interview that Lance has done, read the U.S. Anti-Doping Agency report and three books all in one week.

On the day of the interview, Oprah issued a series of rapid-fire yes or no questions, in which the retired cyclist confirmed that he had blood transfusions and used the banned substance erythropoietin (EPO) during his career -- particularly during all seven of his Tour de France victories.

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"You know it's a good interview when you're done and you get in the car and you say, 'There's not another thing I wish I would've asked him,'" said Gayle. "That's pretty good, and that's how she felt."

The brunch was a part of the festivities surrounding the Presidential Inauguration. Other attendees included Eva Longoria, Star Jones, Kerry Washington and Rosario Dawson.