Darren, whose partner Lynda Bellingham has already been voted off the show, said Ali's heroic performance this weekend deserved to keep her in the competition.
He said: "How she danced at all was a miracle, her whole foot was completely black."
He added: "A lot of people say they are faking an injury but I guarantee you the foot was black and she had to force her foot into that shoe.
"Then she had to do a dance off which was even worse but injuries are just part of it all."
Fellow dancer Lilia Kopylova added: "I'm glad she's through and gets another chance but she couldn't do anything else - she had to dance."
This week, head judge Len Goodman poked fun at the amount of make-up Craig Revel Horwood and Bruno Tonioli wear for the show.
And Lilia agreed, joking: "I'm sure their make up bags are bigger than mine."