Sara Cox is being dropped from BBC Radio 1's breakfast show just months after listening figures revealed the show had shed almost half a million listeners.
But the station's obsession with "ladette" culture is not being abandoned with loud-mouthed, larger than life Chris Moyles, taking over the show in January.
Cox's departure comes three months before her contract for the breakfast show expires, but she is being given a new job - to host Moyles' old show which runs between 3pm and 5.45pm.
The change at the heart of the station's schedules comes three months after it emerged that Radio 1's audience dipped below the 10 million mark for the first time ever.
Rajar figures showed the breakfast show collapsed by almost 500,000 listeners in the three months to June.
"I am absolutely delighted that Chris has agreed to host the new breakfast show," said Radio 1 controller Andy Parfitt.
"He was my first and only choice as successor to Sara who has done a great job over the last three and a half years. In a market that is getting more competitive by the month I think Chris is going to be just what our audience is looking for."
Moyles added: "I am really chuffed. I've said for ages that I am the saviour of Radio 1, now it looks I am finally going to have the chance to prove it!"
And Cox said she was looking forward to a lie-in.
Mr Parfitt recently presented his strategy for the next two years to the BBC's board of governors and is sticking to his plan to bring more cutting edge, specialist shows to the station to attract its core 15 to 24-year-old audience.
Changes he has already introduced include bringing in new blood - including 23-year-old chart show host Wes Butters and Xfm's Zane Low - and ditching some of the station's established talent such as Sarah HB, KC.
The station's weekly reach - the number listening for at least 15 minutes - has fallen to 9.87 million, only just ahead of Radio 4 on 9.6 million.
Last year Moyles took a swipe at his Radio 1 colleague saying he could do a better job in the prized slot.
"I could absolutely kick anybody's arse on breakfast, ever," he said.
He said he barely listened to Cox's show, preferring to watch Channel 4's Ri:se. But in the same interview he cast doubt on whether he even wanted to have a shot at the Breakfast Show.
"Getting up at 4.30 every morning for a little bit more money and more hassle and half a million more listeners - is it worth it?" he asked.
Moyles is renowned for his near the knuckle humour, laddish chat and his appreciation of pub culture.
Both Cox and Moyles have been criticised for using bad language and making sexually explicit comments on air. But the lad and ladette era they epitomise, along with magazine Loaded and Britpop band Oasis, is widely believed to have passed out of fashion.
Moyles was reprimanded by the BBC governors in 2000 for making "ill-judged" sexually explicit comments at 10am on a Saturday morning and BBC 1 bosses censured him for persuading women to undress in the studio.
Cox, who took over the breakfast show from her best friend and original ladette Zoe Ball, has run into a barrage of criticism on several occasions. Her brushes with controversy have included an obscenity-strewn interview with comic Ali G, references to 'shagging' and comments about Jamie Theakston's genitalia.
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