The van was hit so hard, it crashed through the bridge barriers and plunged into Tauranga Harbour.
Mr O'Connor arrived at the scene and without hesitation stripped to his underpants and leapt into the water.
Mr Donkersley, 23, was unresponsive when Mr O'Connor found him.
For nearly 45 minutes, Mr O'Connor supported Mr Donkersley, telling him jokes as he battled strong currents in the dark night to find the shore.
"I didn't want him to know how petrified I really was," Mr O'Connor said today, after winning the New Zealand Police Association Bravery Award.
Eventually, the two men made it to safety, freezing, cramped, exhausted and barely able to stand.
Despite efforts to save him, Mr Woledge, a young father also aged 23, was trapped in the van and died. He was remembered at the Bravery Award ceremony in Wellington today.
The ceremony was made even more poignant with the news Mr Donkersley and his partner had just had a daughter, eight-day-old Millie.
"It's nice to know that another life has come into this world," Mr O'Connor said. "I'm pleased for Ashley and his family."
The two men now share an unshakeable bond.
The policeman and father-of-four said he saw Mr Donkersley as family.
"I feel like I've got this obligation to be part of his life and he feels the same way," Mr O'Connor said.
Mr Donkersley, who came to New Zealand from Yorkshire in 2012, said he had caught up with Mr O'Connor "for a few beers" since and had also visited his house.
He said he wasn't surprised his rescuer won the accolade. "He deserves it and more."
Mr O'Connor joked that it was easier to jump off the bridge than stand on stage and be in the spotlight.
Prime Minister John Key said the New Zealand public recognised that police largely did a "magnificent" job.
Mr Key said O'Connor was unassuming but he put his own life on the line to save somebody else.
"That is the definition of a hero. I think we can all look up to you," Mr Key said at the awards.
The policeman's proud family, including his wife Sharon, brother Jay, and daughter Erin Fowler also attended the ceremony.
Mr O'Connor said he grew up on dairy farms, moving between Waikato towns before settling in Tauranga in 1984.
As a boy, he and friends spent time swimming in local rivers. They especially enjoyed navigating rivers in flood.