O’Connor completed an improbable rise from being an attacking, inconsistent rider not suited to the long rigours of riding a three-week Grand Tour to the heights of finishing fourth overall in the 2021 Tour de France.
O'Connor made the first team switch of his young career in the 2020 offseason, moving across to AG2R-Citroen from then Dimension Data. The 25-year-old had shown flashes of brilliance already, but years of less consistent performance meant that it was just a one-year deal that was signed.
The agreement has turned out near perfect for both parties, with O'Connor bringing a new threat to the team on the overall standings at the big races, and the Australian discovering a new consistency with the French WorldTour squad.
A new three-year deal was the reward for the West Australian at the end of the Criterium du Dauphin, with O'Connor also confirmed for a start at the Tour de France in a GC-focused role.
He went there with muted expectations, a top 10 his hoped-for result in the biggest race in the world while also staying active, looking for stage win opportunities.
"Would you have bet money on me coming fourth in the Tour? I don't think so," said O'Connor to reporters ahead of the final stage of the race.
On Stage 1, things looked even more dire. O'Connor was caught up in the mass pile-up with 45 kilometres to go, the West Australian took damage to his forearm and shoulder, requiring ten stitches. The signs after he battled to the stage finish just under two minutes down weren't good, barely able to mount his bike.
"I couldn't move my arm. I couldn't stand up and move my shoulder," said O'Connor. "I thought my race was over, I was 100 per cent sure I'd broken my shoulder. It was a pretty awful feeling, that on day one of my first Tour de France I was going to be a DNF (did not finish). It would have been very sad after all my hope and support from my friends and family."
O'Connor's rise as a rider to contend on the general classification - only two Australians have finished higher overall than him in Tour de France history - was not scripted. The young Australian showed promise before being pushed into the role of race leader, perhaps before he was entirely ready for it, as O'Connor explained.
"I'd already fallen into this GC role earlier in my career in the Tour of the Alps [in 2018]," said O'Connor, "telling myself I had to be there. But I was too young and inconsistent to finish it off. So here it was maybe believing in my ability and taking the race on rather than just trying to hold on every day.
"I lost it in 2019, but then I regained some self-belief in 2020 and started the season really well. But a series of unfortunate circumstances hit me last year."
O'Connor had to fight through illness and injury in his main target of the year, the Giro d'Italia, and did so with a fine stage victory and a second-place finish on a stage, hints at what was to come in 2021.
His early season performances at Paris-Nice and the Tour of the Basque Country were promising, but top 10 finishes at the Tour de Romandie and Criterium Du Dauphine showed that the 25-year-old was climbing with he best in the world and not looking out of place. However, it's a long way from the lesser build-up races and the enormity of the Tour de France.
"It's by far the hardest race I've ever done, and ever will do," said O'Connor. "Mentally it's very draining, you have to stay alert, concentrating, really make sure you don't make any mistakes. The Tour is a lot more unforgiving than the Giro or Vuelta."
O'Connor's stage win on Stage 9 vaulted him up the general classification, but it was his dogged determination to hang in over the final week of the race that saw him secure fourth overall when other experienced contenders were falling off the pace dramatically.
"My mentality yesterday was simply 'never give up' or crash," said O'Connor. "It's the same today, then on top of that just be careful on the Champs-Elysées. And then 'voila', finished."
O'Connor finished just over ten minutes behind the yellow jersey Tadej Pogačar (UAE Team Emirates) who finished with a total time of 82 hours, 56 minutes and 36 seconds, and shied away from questions about challenging for the top step of the podium in the future.
"The yellow jersey was a long way off, another level and another game," said O'Connor. "I hope one day I can wear the maillot jaune, but I would have to progress in the same way as I did this year to get there. You never know."
The only Australians to finish higher in the French Grand Tour than O'Connor are Cadel Evans and Richie Porte, the West Australian joining an elite club in his debut Tour de France.