Not the 20th most powerful man in the PR business, you'll note, or on Gray's Inn Road, but the 20th most powerful of all in the UK.
To list all those over whom Byrne can lord it would take forever. But here's a few: Paul Dacre, Charles Allen, Gavyn Davies, Roman Abramovich, Bernie Ecclestone, the Health Secretary, the chief rabbi, the manager of Manchester United, John Humphrys, David Trimble, the chief executives of BP, Tesco and Ryanair, and the head of the home Civil Service.
Oh, and Prince Charles, Lord Falconer, Conrad Black and the Duke of Westminster.
And Lord Hutton, Richard Desmond and England manager Sven-Goran Eriksson.
Most satisfying of all for the PR community is the fact that both Byrne and Matthew Freud (at 19, one above Byrne) rank more highly than every newspaper editor bar the Daily Mirror's Piers Morgan. Could the balance of power finally be shifting in the PR industry's favour?
Byrne says: 'I am surprised and flattered, but my bid to use this triumph to leverage a pay rise out of (WS's global CEO) Harris Diamond has already failed, as has my attempt to get into Marie Claire's annual top 100 Media Beefcakes list.'
Diary can't help observing that Peter Mandelson, a columnist for GQ, was best man at Byrne's wedding. Surely just a coincidence.