Betty White in SNL

NBC can thank Betty White for being a friend and bringing in big numbers for Saturday Night Live.

White's SNL hosting debut was the No. 1 telecast of the night, topping prime-time programs, and netted an 8.8 rating/21 share to post the late-night sketch-comedy show's best numbers in 18 months, according to early estimates.

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The Nov. 1, 2008, episode, hosted by Ben Affleck with appearances by then Republican presidential candidate John McCain and Tina Fey as Sarah Palin, drew a 9.0 rating/20 share.

White's telecast — which featured musical guest Jay-Z and alums Fey, Amy Poehler, Molly Shannon, Maya Rudolph, Ana Gasteyer and Rachel Dratch — earned a 5.1 rating in the 18-to-49 demographic, just shy of the Nov. 1 episode's mark of 5.2.

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Compared with last year's episode this weekend — with host Justin Timberlake and the debut of the "Motherlover" Digital Short — White's episode saw a 66 percent growth in the markets tracked by Nielsen.

Final numbers, including viewer totals, are due Thursday.