BILLY Knott is standing outside the warehouse where he works and he can feel his bottom lip start to tremble.

On Thursday, it will be four years since City recorded one of the most famous results in FA Cup history.

THE biggest upset in the eyes of many, especially the 6,000 travelling fans who were fortunate enough to be at Stamford Bridge to witness Jose Mourinho’s Chelsea toppled after giving away a two-goal start.

The emotion bubbles up in Knott’s voice as he recalls being at the epicentre of such a moment. The significance of the date always hits the former Bantams midfielder.

“As soon it comes round again, you remember those feelings you had at that time,” he said. “I can feel I’m going now just thinking about it.

“It’s still hard to describe. It was just a mental day.

“You will never forget how outrageous it was, all the fans behind the goal – just incredible.”

The four years between then and now have been tough for Knott, who made 79 City appearances.

He admitted drinking too much as opportunities became more limited in his second season. Off-field problems saw him spiral into depression and seeking help to get back on his feet.

After spells with Gillingham, Lincoln and Rochdale, he returned to his Essex roots and currently combines playing for Concord Rangers in the Conference South with a full-time day job at the club owner’s asbestos management company.

At 26, Knott still has ambitions to climb back up the ladder and there are offers he is considering in League Two.

The canvas on his bedroom wall remains a powerful spur.

Three pictures take pride of place from that miracle of Stamford Bridge – Knott on goalkeeping coach Lee Butler’s back at the final whistle, Knott with Stephen Darby saluting the fans, Knott submerged by supporters as he hands his shirt to a close pal.

“People know what I’ve been through but when you think about stuff like that it’s brilliant. Nobody can take that away.

“We deserved to beat Chelsea – it wasn’t smash and grab but a well-fought game-plan and we took our chances when they came along. It was just one of the best days ever.

“We had a good team – and a good bench with people like Yeatesy (Mark Yeates) and Billy Clarke coming on. That was great to have that quality for League One – but then you look across and saw them bringing on (Cesc) Fabregas and (Eden) Hazard!

“I couldn’t even walk afterwards. We were moving side to side all the time.

“I was just concentrating on not giving the ball away. I knew that if I did, we wouldn’t be getting it back!

“I’ve watched the whole game back three or four times and before I came off with cramp, I’m basically playing in the back four.

“You wouldn’t even think about doing that as a number 10 in League One. I’m standing next to Davo (Andrew Davies), although he’s winning the headers.”

The magnitude of City’s 4-2 victory - the first time a Jose Mourinho side had conceded four at home - only sunk in when the Portuguese strolled into their dressing room.

Knott recalled: “We were all jumping around and then Mourinho walked in. Everyone went completely silent.

“He is shaking all of us by the hand and saying ‘it takes big b*lls to beat us like that.’ That was the moment when you think, ‘what has just happened?’

“He told us to go and see their kitman if we wanted any shirts or anything. It just summed him up as a person.

“He must have been absolutely fuming to lose to a team two leagues below. But he showed the respect that we deserved on that day.”

Knott pauses, puffs out his cheeks and gathers his thoughts. Recalling such magical times highlights what has slipped away - and what he is determined to taste once more.

“I want to get back to full-time football and sort myself out. I feel that I’m getting there.

“I’ve had a few offers from clubs and I’m just waiting. It’s one of them about moving away from home again but that’s what you’ve got to do to make it happen.

“I’m in a better place. It’s still going to hurt sometimes but everyone makes mistakes and you learn from them and be a bigger person.

“I’m fed up going to work at 7am every day.

“Speaking about football again, I just want to go play now. But there are too many trucks around me!”