It wasn't a particularly shocking result with both in the danger zone on the judges' scoreboard last night.
Anastacia and her pro partner Brendan Cole danced the Rumba to 'The Way We Were' by Barbra Streisand to score 27 points.
Naga and her pro dancer Pasha Kovalev had performed the Charleston to 'Minnie the Mermaid' by Firehouse Five Plus Two and had 24 points from the panel.
The two were in the bottom three alongside Ed Balls - who scored the lowest marks of the series to date - but he avoided the dance off once more.
As usual, the results from the public vote were added to the judges' scores to decide the bottom two in the dance off.
First to be announced as in the dance off was Naga.
Len Goodman told her: "100% your confidence was terrific, you came out and really performed. Keep that level of performance, keep your timing clean and clear, good luck."
Tess then confirmed that Anastacia was also in the dance off for the second time. She said: "I can dance off though! Let's go for it!"
Tonight's Strictly Come Dancing 2016 results
Anastacia and Naga both danced their routines from Saturday again before the judges picked who to stay.
Craig Revel Horwood said: “The couple who I thought danced actually the best in this dance-off this evening was Anastacia and Brendan.”
Darcey Bussell added: “It’s always incredibly difficult when it gets to this and very hard but the couple I would like to save because of their performance value and natural artistry is Anastacia and Brendan.”
Bruno Tonioli commented: “Well I would go for the couple that delivered a much cleaner, slicker and more rounded performance, very convincing tonight, Anastacia and Brendan.”
Although he didn't need to vote, Head Judge Len Goodman said he agreed with his colleagues and that he would have also saved Anastacia and Brendan.
As a result it was Naga and Pasha who found themselves leaving the competition.
Strictly Come Dancing 2016 results next Saturday and Sunday night on BBC One.