The actress, who died in December at the age of 60, was seen reprising her role in Channel 4's Catastrophe.
Fisher filmed the scenes for the programme days before she suffered cardiac arrest on a flight from London to Los Angeles.
Writing on Twitter, Esther MacCarthy said the episode was "hard to watch - but what a swansong".
"Thank you [creator, writer and star] Sharon Horgan for writing Carrie Fisher one of her funniest and feistiest roles," she added.
Fisher had a recurring role in Catastrophe as Mia, the irritating and foul-mouthed mother of Rob Delaney's character.
She played the role in earlier seasons of Catastrophe, but did not appear in the third series until the sixth and final episode.
David Lopez-Edwards wrote: "Hadn't watched before but tuned in to Catastrophe tonight for the majestic Carrie Fisher. Gutted she's no longer with us. What a loss."
"Watching the final episode of Catastrophe and already crying by the Channel 4 voiceover guy saying 'This one goes out to Carrie Fisher'," tweeted Luke Karmali.
The episode ended with a message on the screen that read "For Carrie", in tribute to the late actress.
Delaney and Horgan have previously said they "idolised" Fisher and that the entire third series was a tribute to her.
Horgan said: "She was part of the gang and we really feel very privileged and honoured.
Fisher and her mother, actress Debbie Reynolds - who died the day after her daughter in December - were remembered at a public memorial in Hollywood last month.
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Fans have heaped praise on Carrie Fisher after her final TV appearance aired on Tuesday evening.