A commuter revealed he has raced a man into work every day for a year - without him ever realising.
Adam Woollard captured a cheeky viral photo of his fast-paced "worthy adversary" who he usually walks past at around 8.30am.
However one day 28-year-old freelance script writer he lost his pace and was defeated by his adversary.
It was then that Adam took a quick snap and penned a post about him.
He said he felt happy when he beat him on a previous occasion due to an energy drink pit stop.
Adam, from Tufnell Park, North London, said: "I would see him pretty much every day I was working at about 8.30am approaching Aldgate East.
"I would follow him for around ten minutes before we'd split ways at the traffic lights that go down Commercial Street, which for me is where the race ended.
"That would be when I would know whether I'd beaten him or not.
"He often beat me because he was quite quick, he wasn't as tall as me but he had two legs and he knew how to use them - he knew what he was doing.
"I saw him as a marker for being on time for work and if I didn't see him I assumed he was ill, then I was worried about him, wondering whether he was running late, early, or if I was running late.
"This happened for about a year.
"I only ever saw the back of him and from the back he looked like one of my friends.
"I wasn't brave enough to turn around and look at him - I didn't want to ruin it for myself by seeing his face."
Adam originally shared a post about his smartly-dressed competitor back in May 2018, which went viral last month.
Adam's original post read: "He doesn't know it, but me and this guy race on our walk to work every day.
"Today he got the edge on me because I had to stop and tie my shoelaces but usually I pip him just before the T junction.
"Never spoken to him, but he's a good competitor. A good kid. Strong walker.
"One time he stopped in to get (I think) a lucozade from a Londis and it was the most exciting thing that's ever happened to me.
"I f***ing smashed him that day."
Adam walked from Archway to Aldgate East on the three days he was in the office.
The 10-mile round trip took an hour and 45 minutes each way.
He said as soon as he noticed his soon-to-be competitor walking the same route at 8.30am, he decided to race him.
Adam said: "When I'd see him I would walk behind him for a while just to feel his pace and then I would wait until a good moment.
"I'd have to go in front of him quite late into the game on Commercial Street so he couldn't sneak up behind me and overtake at the last minute.
"I'd have to leave it to the last possible second to go 'right I'm in front of you now and you cannot beat me because we're at the end of the race'."
In the viral Facebook post, Adam reminisced about one time he left his smartly-dressed competitor trailing in his wake.
Adam said: "One day I think he went in for a little drink - a lucozade or an energy drink probably.
"At first I thought 'this doesn't feel like a real achievement to beat him by this much because he's gone in there'.
"Then I thought 'in F1 they have pit stops and that counts'. So I decided it was still winning, it wasn't by default or a moot race, so I won.
"I was way in front of him - I left him in the dust - as it's busy in shops at that time in the morning with people getting their morning bits.
"It was end game, no question."
Flush with success, Adam shared his emphatic victory with pals on Facebook.
Adam said: "It was a high that took me through the day.
"I didn't bandy it about the office because I didn't want to be crass, so I just kept it to myself and have a nice little warm glow throughout the day.
"I put it online because I thought it was something that people in London and other cities would relate to, it feels quite British for some reason, but I didn't know how far it would go.
"When I'm walking along the street generally people are going into over-drive mode to take over the person in front because they're walking too slowly.
"So when you find someone who's clearly in the same sort of range as you it becomes a challenge , that's the best outcome you can get. You've made a nemesis and, in a way, a friend."
He added: "I hope he was aware of me. I think he saw the back of me a few times but I don't know if he saw it as a race and if he did, maybe he would have beaten me.
Now Adam has a new side job two nights a week at a pub and, despite it being only a five minute walk, he has discovered a new adversary - a "very quick" woman who he pits himself against.
Another photo shows the seemingly unaware woman as he raced behind her in his bid to overtake.
"In my head she's called Taylor - because she's swift. She has locomotives for legs, I've never got past her," he said.
Adam said that if he beat her, he could quit his job and hunt down his next competitor.
"I want to be the undisputed champion of the competitive walking circuit," he claimed.
"Some people would say that's a pipe dream but I think it's possible.
"I think if I beat her I'll quit my job there and I'll find somewhere else and then take on the champion of that track."