A favourite to win from the start, the bookies had placed him just behind Alexandra Burke in the odds for who was going to win the whole series. Of all the styles of dance performed in Strictly, Aston had achieved the highest marks for four of them.
If you add up all the points awarded since week one, Aston was behind only Alexandra and Debbie McGee in the overall scoreboard. But now, shockingly, he's out at the half-way point.
How did this happen? And just what went wrong for the former JLS singer?
Up until this week, Aston and Janette Manrara had barely put a foot wrong, with the pair not receiving a score lower than 7 from any of the judges. Aside from week 5 when all of the celebrities' scores were significantly lower owing to Bruno Tonioli's absence from the panel, Aston hadn't ever been given a score lower than 31.
Just the previous week, his Halloween-themed Paso Doble landed a total score of 38, being awarded two 10s from judges Darcey Bussell and Bruno. His Trolls-themed Cha Cha Cha in Movie Week was one of the highlights of the series, being awarded an 8 from Craig Revel Horwood and 9s from the other three judges.
And then on Saturday, his Viennese Waltz landed a score of 4 from Craig. Viewers called it "harsh", and the studio audience and other celebrities seemed somewhat speechless and taken aback by Craig's scoring.
This week more than any other, it felt as though Aston was being somewhat under-marked for a performance which - although wasn't perfect - was of a far higher standard than some of the other celebrities' dances. Craig for example gave Ruth and Anton - complete with their slapstick fall - the very same score of 4.
With scores of 7 from the other three judges, it left Aston and Janette in the danger zone. On this week's leaderboard, they were second from the bottom just ahead of Ruth and Anton - a dramatic difference to last week when they were second from the top behind Debbie McGee and Giovanni Pernice.
Being so near the bottom, you might presume that Aston would have received a surge in votes from the public eager to save his bacon. But as he landed in the bottom two, this clearly didn't happen.
Perhaps viewers presumed enough other people at home would vote for him for this reason, and so they chose to save someone else? Maybe they thought that if Aston did find himself in the dance off, he would be the celeb who the judges would save from elimination, particularly if he was up against the likes of Ruth Langsford, Jonnie Peacock or Susan Calman?
Or maybe he just hasn't connected with viewers in a way that makes them want to vote for him. It can be difficult for performers like Aston or Alexandra, as they come into the start of the competition with viewers expecting great things. When they are so accomplished from day one, it's a bit predictable and a bit - dare we say - boring. There's no 'journey' to be had.
However, it still came as a surprise when he faced Mollie King in the dance off, and even more surprising when the judges chose to save Mollie. Unlike Aston, all her scores each week have been under 31. Her highest ever mark was a 30 for her Sound of Music-inspired American Smooth in Movie Week.
After finding herself in the bottom two for the second week running, it seemed almost inevitable that the judges would send her home and save Aston. While Darcey and Bruno voted to keep Aston in the competition, it was Craig and Shirley Ballas - who as Head Judge has the deciding vote in the event of a tie - who opted to save Mollie.
"On technical accuracy, beautiful flow and full engagement during the dance, I’m saving Mollie and AJ," Shirley explained.
Should the judges should have looked at Aston and Mollie's performance over the whole seven weeks? Sure, Aston had a duff dance on Saturday - but does that mean he deserved to go home after all the amazing routines he's performed so far?
Either way, it's undoubtedly the biggest shock in Strictly 2017. So far.
Strictly Come Dancing airs next Saturday on BBC1