The gay "wedding", said to be the first in the Anglican Church, was celebrated by clerics in defiance of a ruling by the Archbishop of Canterbury, who has explicitly banned formal blessings of same-sex partnerships, especially if they resemble marriage.
The Rev David Lord, formerly of Hamilton, walked down the aisle with hospital chaplain the Rev Peter Cowell, 50, at the 12th-century St Bartholomew the Great Church, in the City of London.
The pair had already registered their civil partnership.
There were bridesmaids and best men, an exchange of vows and rings, and a showering of rose-petal confetti. Only the bride was missing from the ceremony, attended by 300 guests.
The church's rector, the Rev Martin Dudley, defied his bishop to conduct the traditional ceremony for the two gay priests, London's Sunday Times reported.
It is understood the Bishop of London, the Rt Rev Richard Chartres, asked Mr Dudley not to offer such a ceremony. His decision to ignore this request leaves the church's guidelines in tatters and brings the Anglican Communion to the brink of irreversible schism.
"I certainly didn't do it to defy anyone," Mr Dudley said. "I have done what I believe is right."
A Church of England spokesman said last night that it was a "fairly serious" breach of the House of Bishops' strict guidance on same-sex ceremonies.
The fallout for Dr Lord, who was ordained at Waikato Cathedral Church of St Peter in December last year, had been swift. In a joint statement with the Bishop of Waikato yesterday, he said he "felt it appropriate to lay down his clergy licence". This means he is unable to work as an Anglican priest.
News of the "wedding" in London emerged days before a crucial summit of the Anglican Church's conservative bishops and archbishops, who are threatening to split the worldwide church over the issue of homosexual clergy.
Some may try to argue that the relationship is not legally recognised as a marriage. But there can be no doubt that in every other respect this service constituted a church wedding.
Among those attending were some of the most senior Anglican clergy, including Canon Robert Wright from Westminster Abbey, chaplain to the Speaker of the House of Commons.
"It was incredibly grand - the most spectacular wedding I've ever been to," a guest said. "They had a 10-tier wedding cake. I've never seen a cake that big."