Britney Spears gives "How I Met Your Mother" its highest rating

Britney Spears' appearance in CBS sitcom 'How I Met Your Mother' gave the show its highest rating ever.

The show spiked to a series high 4.5 preliminary rating among adults 18-49, even as the rest of the CBS comedy lineup fell from last week's record-setting return to original episodes, according to the Hollywood Reporter.

The Toxic star, 26, also received fairly positive responses from the critics.

"Britney the Trainwreck showed how she can still be Britney the Performer," said the Associated Press.

"Spears proved she can act every bit as well as she can sing," wrote the New York Daily News.

"Brit looked slim, (OK she was behind a desk), trim and gorgeous," states the New York Post.

Britney's role on the show, her last sitcom appearance since guest starring in Will & Grace in 2006, was seen as the start of a possible comeback for the troubled singer.

Media and crisis management consultant Robbie Vorhaus told the USA Today newspaper: "This will be remembered as the beginning of the return of Britney as an actress, a personality, as someone trying to be normal in a pretty crazed world. Good for her."