Pop star Britney Spears' appearance on US TV comedy How I Met Your Mother has pulled in almost 3m extra viewers.
The CBS show attracted 10.6m people on Monday - its highest ratings this season, according to official figures.
The boost is likely to secure a fourth series, which has averaged 7.8m viewers during its current run.
Spears, whose assets are currently controlled by her father, was praised for her performance as a doctor's receptionist in the show.
The New York Daily News said: "Spears proved she can act every bit as well as she can sing."
"Brit looked slim, trim and gorgeous," added the New York Post.
Spears' father is in control of her affairs until 31 July
Alison Godges, a student at New York University who watched Monday night's show, said: "She looked like the Britney we used to know. Long blonde hair and great make-up. She was funny too."
The star's ditzy character had a crush on the comedy's main protagonist, Ted, and flirted with him badly.
Spears, who was admitted to a psychiatric ward and lost custody of her two sons earlier this year, said working on the show was "terrific".
Meanwhile, a legal challenge to her father's conservatorship of her affairs was dismissed by a California court.
A judge ruled that he did not possess sufficient powers to grant an appeal, lodged on the grounds that Spears had not been given enough notice that the order was being implemented.