The West Australian was unable to keep up with the hectic pace set by the peloton in the closing stages of the 220 kilometre ride from Binche to Longwy, as up the road ahead of him Tadej Pogacar won his seventh Tour de France stage and claimed the yellow jersey.
It was another cruel chapter in what's been a rough first week of the race for O'Connor, who crashed in Stage 2 then had a puncture at an inopportune moment in yesterday's Stage 5, losing over three minutes due to not being able to regain the group of favourites.
A dejected O'Connor admitted after Stage 6 that the crash from the second race day was still affecting him, visibly disappointed as he dealt with the high possibility of his podium aspirations being over and done with.
"I'm not really sure what to say," he said after crossing the line.
"I could cry. I'm really disappointed today."
The 26-year-old was asked whether it case of the rapid pace of the peloton that had caught him out.
"I'm still suffering from this crash, it's not like anything's changed out there," said O'Connor.
"From the Dauphine, to Catalunya, this is how I've been racing all year. I just don't know what to say."
After finishing fourth overall with a stage win at last year's Tour, O'Connor was feeling confident and ready to go one better in this year's race, but the struggles have piled up over the first week and made it extremely difficult to make inroads in the general classification.
Now sitting 52nd overall and 7 minutes and two seconds behind the maillot jaune, he may have to look to a different strategy for the next two weeks, be it going for stage wins in the mountains where he triumphed last year or working for another from his team such as Benoit Cosnefroy.
There is a lot of racing left and O'Connor may not just give up hope yet, with tomorrow's first mountain stage a great opportunity to try and attack if recovered from his injuries.
The Tour de France continues with Stage 7, the first mountain stage of the race, finishing atop the Planche des Belles Filles. The race broadcast starts at 8.55pm AEST on the SBS ŠKODA Tour Tracker, with the SBS television coverage starting at 9.30pm AEST.