The 29-year-old and his professional dance partner Janette Manrara found themselves in the bottom two this week along with Mollie King and AJ Pritchard.
Both couples had to perform again but the judging panel chose to save The Saturdays singer, 30, over the JLS member, 29.
Fans immidiately called the show a fix as Shirley Ballas chose to save Mollie King.
Aston and Janette, 33, performed their Viennese Waltz to Who’s Loving You by Jackson 5, while Mollie and AJ, 22, did their Foxtrot to Call Me Irresponsible by Connie Francis.
Giving his decision, judge Craig Revel Horwood said: “Both couples improved on the night which was wonderful to see but based purely on technique for me, the better dance of the evening goes to Mollie and AJ.”
However, Bruno Tonioli seemed to disagree with his fellow judge and explained: “I want you both to stay! If it was up to me I would keep you both because you’re both wonderful, both much improved, you all seem to have ironed out a lot of little problems you had on Saturday night.
“But one couple really, I felt transformed their performance tonight and it had much more power, much more impact, it flowed more and for that reason I would like to save Aston and Janette.”
Darcey Bussell sent things into deadlock after she named Aston and Janette as well.
It was up to Strictly Come Dancing head judge Shirley Ballas to give the final and casting vote: “Well again a very difficult choice, two fantastic couples and it’s very difficult to do. On technical accuracy, beautiful flow and full engagement during the dance, I’m saving Mollie and AJ.”
The news comes as something of a shock after Aston came second place on the leaderboard last week and was previously tipped to even win the whole competition and lift the Glitterball Trophy.
Reflecting on leaving the competition, Aston told host Tess Daly: “Honestly, every second of this, I’ve had friends who have done the show before and they’ve gone ‘you’re going to have the most amount of fun from start to finish whatever it is’ and honestly they weren’t lying!
“Everything, from this lady to every single person in here, these four judges, yourself, Claudia, all you amazing lot up there that I get to see and spend so much time with. I’ve made some amazing friends and honestly I’ve had the best time, it’s been amazing.”
His exit from the competition comes after fans were left fuming when Craig, 52, gave him a measly score of four that put him second from the bottom on the leaderboard.
Fans have also been left raging at head judge Shirley Ballas for casting the deciding vote to send Aston home.
Strictly Come Dancing continues on BBC One next Saturday at 6.45pm.