Floyd Mayweather vs Conor McGregor is, after many months of negotiating, posturing and plenty of talking, in the final week countdown. Next Saturday the once-retired all-time great boxer Mayweather will take on UFC's biggest star McGregor in Las Vegas with millions more watching around the world.
After all the speculation about whether we would have the fight, the last few months have seen much name-calling and animosity on both sides, as the rivalry intensifies ahead of the big day.
Depending on your point of view, it will either be boxing match of the millennium or a cross-code money-spinning abomination. Whichever camp you're in, here's everything you need to know about the fight between a boxer with a 49-0 record facing a man who has never taken part in a professional boxing fight.
What date is the fight and at what time?
The fight is happening on Saturday 26 August. While the times haven't been announced, it will certainly be a late night or very early start for viewers in the UK, so expect to be up well into Sunday 27 August, and possibly calling in sick on Monday 28. It's likely to be after 4am BST, but may start closer to 5am.
Where is the fight taking place?
The bout will be housed in the T-Mobile arena on the Las Vegas Strip in Nevada. The venue has held major fights in the past, including UFC 202, in which McGregor beat Nate Diaz on points.
How can I watch it on TV?
Sky Sports Box Office will show the hugely-anticipated clash for £19.95 in the UK and €24.95 in the Republic of Ireland. You can buy the fight online here, through a Sky box or online the telephone - 03442 410 888. If you're calling from the Republic of Ireland, it's: 0818 220 225.
What if you do not have Sky?
Fear not, with the Sky Sports Box Office app you can watch the fights live via your PC/Desktop/MAC, NOW TV box, iPhone, iPad, Android phone or Android tablet.
It's simple to sign up, pay and watch - create an account and pay at www.skysports.com/boxofficelive.
What are the odds?
Bookies immediately predicted a Mayweather win. William Hill put the veteran fighter at 1/11 favourite. He's now 2/9 with just over a week to go.
Oddsmaker Nick Bogdanovich said the odds would be even more lopsided if it wasn't for the deluge of small bets expected to come in from UFC fans on their fighter.
"Realistically if we were just putting up a number and didn't have to take bets on it, Floyd would be 1/100," Bogdanovich said. "But this will be a very, very big betting fight for sure, one of the biggest ever."
How has the rivalry developed in the last few weeks?
The pair embarked on a four-day tour last month that took in trips to London, Los Angeles, Toronto and New York.
The tension reached a crescendo at the SSE Arena in Wembley, when after trading profanities, the UFC fighter said: "Four years ago I fought in London at The Forum in front of about 500 people. Now here I am about to quadruple my net worth with one half a fight. Sign me up. No one is going to kick, knee or elbow. And it’s against this little b****."
There was also controversy in New York when McGregor was accused of racism after saying "I'm half-black".
What are their fighting records?
Mayweather retired in 2015 with an unblemished 49-0 professional boxing record.
He is widely regarded as one of the best defensive fighters ever, and prides himself on his ability to evade punishment with his skillful movement about the ring while making adjustments against opponents on the fly.
A win for Mayweather would move him ahead of former heavyweight great Rocky Marciano, who also retired with a perfect 49-0 career record.
McGregor, the UFC's reigning lightweight champion and former featherweight champion, is known as much for his bravado as for his explosive knockout power inside an MMA octagon.
The 28-year-old Irishman became the first UFC fighter to hold two belts simultaneously when he knocked out Eddie Alvarez in New York last November for the lightweight championship.
The UFC stripped McGregor of his featherweight belt shortly after that fight when he announced he would be taking some time off after he and long-time partner Dee Devlin had their first baby in May.
Known for his devastating striking and highlight-reel knockouts, McGregor is also quick and irrational on his feet, but few would back him to beat one of the most complete boxers of all time.
What are the rules of the fight?
The fight will be held under boxing rules, presenting a huge challenge for mixed martial artists McGregor as he faces off against one of the greatest defensive boxers in history.
Adding to McGregor's challenge, the fighters will be using 10-ounce boxing gloves instead of the smaller UFC gloves and he will not be allowed to use the leg kicks or takedowns that are used in mixed martial arts.
McGregor will weigh in at 154 pounds, UFC president Dana White told ESPN. The pair will wear 8oz gloves, which you can read more about here.
Who is referee, who are the judges?
REFEREE: Robert Byrd
JUDGES: Burt Clements, Dave Moretti and Guido Cavalieri
Vastly experienced American referee Robert Byrd will be the third man in the ring, with the judges confirmed as Burt Clements, Dave Moretti, both American, and Guido Cavalleri, of Italy, after McGregor's team had requested an international judge in the trio.
Byrd refereed Mayweather's unanimous points decision victory against Robert Guerrero four years ago. Mayweather's last three fights were refereed by Kenny Bayless, but he was ruled out after critical comments from McGregor's head coach John Kavanagh.
Byrd, a veteran of major fights, is seen as a referee who allows the fighters to work on the inside, often keeping a respectful distance, using his voice to command the bout and make boxers break.
Byrd has also recently bossed the high profile contests between Andre Ward and Sergey Kovalev, Saul 'Canelo' Alvarez's win over Miguel Cotto and George Groves' unsuccessful challenge of Badou Jack.
What have they said?
Floyd Mayweather Jr
In the first stop of a four-city media tour promoting the fight, told the 20,000-strong crowd in Los Angeles: "I don't care if it's a ring or it's an octagon, I will kick ass. I don't back down for anybody.
"You line them up and I will knock them down. On August 26, I'm gonna knock this b**** out too."
McGregor retorted: "You haven't knocked anyone out in about 20 years."
Mayweather added: "We talking about from the nineties to now, world champion 18 years, but it is no problem. I'm not the same fighter as I was years ago, but I got enough to beat you.
"You will wave that white flag. You are going out on your face or your back. Which was do you want to go? All you need to do is show up and I will do the rest.
"God only made one thing perfect, and that is my boxing record."
The Irishman was the crowd favourite at the opening press event as he made fun of Mayweather's IRS troubles - a lack of cash prompted him to file an appeal with the IRS (Internal Revenue Service) regarding overdue taxes - and promised to flatten an aging fighter.
"He's in a track suit," McGregor told the crowd of more than 11,000 people. "He can't even afford a suit anymore."
"I am honoured to be here, to give you this spectacle," McGregor said. "His little legs, his little core, his little head, I am going to knock him out inside four rounds, mark my words.
"I am a young, confident, happy man that has worked extremely hard for this.
"I am just up here embracing everything. No-one can do anything to me. I am just enjoying myself and having a good time.
"He will be unconsciousness in four rounds. He has never faced this. I don't fear him.
"All these rules, all these restrictions, it doesn't faze me; it amuses me. It is funny to me all these rules.
"All I need is a gum shield. Line me up to the ring and I am good to go."
Who are celebrities backing to win?
Here is a selection of big names here.
And who do you think will win?