The 'Fat Actress' star and her partner Maksim Chmerkovskiy came second in the leader board on the night with their Cha Cha cha to Cee Lo Green's 'Forget You', with judges Carrie Ann Inaba and Bruno Tonioli both awarding them eight points.
The couple received a total of 23 out of a possible 30 and finished just behind 'The Karate' Kid' star Ralph Macchio.
Speaking after the event, a shocked Kirstie said: "I did work hard, and I'm going to work harder now. I've had a taste of an eight, I want a nine."
Kirstie - who has admitted she wanted to take part in the show to lose weight - was the last to perform, and Bruno confessed her footwork was among the best on show.
He said: "Your foot placement was the best of the night."
Head judge Len Goodman added: "It was fun it was cheeky and it made me feel good."
Pittsburgh Steelers player Hines Ward was also highly acclaimed for his cha cha cha with partner Kym Johnson, with the audience on their feet for his dance.
Among the surprises of the night was Playboy owner Hugh Hefner turning up to watch his former girlfriend Kendra Wilkinson and talk show host Wendy Williams putting in a less than confident performance and scoring just 14.
Commenting on the dance, Len said: "You need to unleash the beast. I thought, 'Here we go, loud and proud - you got your dumplings boiling over.' But it was quiet. It was timid."
No stars were eliminated from the first show.
'Dancing with the Stars' total scores:
Ralph Macchio and Karina Smirnoff: 24
Kirstie Alley and Maksim Chmerkovskiy: 23
Chelsea Kane and Mark Ballas: 21
Hines Ward and Kym Johnson: 21
Romeo and Chelsie Hightower: 19
Chris Jerico and Cheryl Burke: 19
Petra Nemcova and Dmitry Chaplin: 18
Kendra Wilkinson and Louis Van Amstel: 18
Wendy Williams and Tony Dovolani: 14
Mike Catherwood and Lacey Schwimmer: 13
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