If anyone was hoping for a side-by-side photo of the identically dressed women, they were out of luck.
Palin's guest shot, widely anticipated since Fey began imitating her a month ago, led "Saturday Night Live" to its highest mark in overnight Nielsen Media Research ratings since March 1994, when assaulted skater Nancy Kerrigan was guest host.
Although a complete audience estimate for the rest of the country won't be available until later in the week, it is likely to be around 14 million.
For the first half-hour, when Palin first came out, the audience was about 17 million. That's pretty impressive for a TV program around midnight. The week before, only two other shows in prime time had a bigger audience, Nielsen said.
Her running mate, John McCain, watched clips of the broadcast on Sunday.
"Did you catch Sarah Palin on 'SNL'?" he asked a crowd in Toledo, Ohio. "She did a great job."
In the show's opening, Fey's Palin said at a news conference: "First off, I just want to say how excited I am to be in front of both the liberal elite media, as well as the liberal regular media. I am looking forward to a portion of your questions."
Moments later, the camera cut away to the real Palin watching a television monitor alongside the show's executive producer, Lorne Michaels.
Palin stood quietly as Fey's "30 Rock" co-star Alec Baldwin came by, mistook Palin for Fey and pleaded with Michaels not to let the actor go onstage with the governor.
"This is the most important election in our nation's history and you want her, our Tina, to go out there and stand with that horrible woman?" Baldwin said.
When Michaels introduced him to Palin, Baldwin feigned embarrassment and replied: "I see. Forgive me. I feel I must say this: You are way hotter in person."
Palin got even, saying: "Thank you, and I must say, your brother Stephen is my favorite Baldwin brother." Stephen Baldwin is a born-again Christian who attended the Republican national convention in 2004.
Alec Baldwin ushered her onstage past Fey, where Palin delivered the show's traditional opening: "Live from New York, it's Saturday night."
Palin later appeared alongside Seth Meyers on "Weekend Update," declining to perform a rap song that had been written for her. Amy Poehler "filled in" for Palin as actors dressed as Eskimos, Palin's husband, Todd, and a moose danced across the stage.
"All the mavericks in the house, put your hands up," Poehler rapped, as a bopping Palin followed the instructions. "All the plumbers in the house, pull your pants up."
Palin's appearance had been confirmed by the McCain campaign a day earlier. "Saturday Night Live" had been reluctant to do so, feeling embarrassed when it announced Barack Obama would show up for the season's first show and he canceled hours ahead of time, but the early word created heavy anticipation.
Michaels owes Palin a debt of gratitude. "Saturday Night Live" so far this season has been up 76 percent over last year at this time, Nielsen said.
Even beyond that, the Fey skits have gone viral over the Internet, drawing more attention to the show. One study last week said only one-third of people who had seen Fey's impersonations did so on live TV; the rest saw them on DVRs or on their computers.