US singer Michelle Williams became the sixth celebrity to leave the competition, after her Paso Doble proved as unpopular with viewers as it was with the judges.
They said her dance with partner Brendan Cole "lost balance" and was "very stiff".
The combination of judges' scores and phone votes meant Williams and actress Felicity Kendal were in the bottom two.
But it was the former Destiny's Child star who was eliminated. Judge Bruno Tonioli said: "It was the right energy but you lost it so many times."
He added: "You need the aggression, but the arms – all the lines were not flowing all the way through. You lost balance.
Ann Widdecombe survived despite coming last in the judges' scores.
Her foxtrot was described as "laboured" and "disorientated". She was awarded 20 points out of a possible 40.
The 63-year-old wore a pink dress and shawl as she danced to Frank Sinatra's You Make Me Feel So Young with partner Anton du Beke.
Speaking after her elimination, Williams said: "I'm sad about going, but you know, at least I don't have to worry about being on the bottom two again."