Britain's David Haye admitted all his achievements in boxing would be forgotten if he loses to heavyweight rival Wladimir Klitschko on Saturday.
Haye, the WBA title-holder, faces the Ukrainian IBF and WBO champion at Hamburg's 45,000 capacity Imtech Arena.
On Friday, Haye weighed in at a trim 15st 3lb (213lb), while Ukrainian Klitschko was 17st 5lb (243lb).
"It all comes down to this, everything else will be forgotten if this doesn't go right," said 30-year-old Haye.
"This fight is everything to me. All the stuff at cruiserweight and winning the WBA title will mean nothing if I don't beat Klitschko.
"I have to prove to the world I am the number one heavyweight on the planet. A lot of people think that's not the case, but I've always risen to the occasion and Saturday night will be no exception."
For what will be only his sixth fight in the division, Haye weighed in 2.5lb heavier than for his last fight against Audley Harrison, which was the lightest he had been as a heavyweight.
"There was never a plan to come in at any particular weight," said the Londoner.
"I just made sure I trained really hard and I was healthy. I've eaten well, I haven't had any junk food, I haven't cut any corners, so this is my ideal fighting weight."
Between 500 and 1,000 British fans crammed into a Hamburg sports shop to witness Haye and Klitschko come face to face for the final time before fight night.
And Haye, egged on by his chanting supporters - "Klitschko, Klitschko, where's your fans" was just one of the taunts - continued his war of words during the traditional face-off.
"I don't think I can say what I was saying to him up there," said Haye, who has 25 wins (23 knockouts) and one defeat from 26 professional fights.
"It wasn't nice, I wasn't telling him I love him, put it that way."
Haye said he was blown away by the travelling support - "if this is anything to go by, Saturday night is going to be absolutely tremendous" - while his fans did not appear to be upset by his pre-fight trash-talk.
"We're behind him 100% - none of his stunts bother me in the slightest," said Gary Webber from Sunderland. "It's all part and parcel of boxing and I think he's got inside Klitschko's head."
John Ferguson, from Derby, added: "How anyone wouldn't get behind a fellow Brit is beyond me."
Meanwhile, Haye revealed he had stopped sparring three weeks ago, a week earlier than normal.
"I was getting everything off in sparring that I wanted to get off in the fight," said Haye.
"[Trainer] Adam Booth said 'what's the point in doing the same thing over and over again, you've got it, let's work on some other stuff - conditioning and timing and speed - and I feel great."
Haye also revealed he has concerns about the referee for the fight - Booth called for Genaro Rodriguez, who has been in charge of four of Klitschko's fights, to be replaced, to no avail.
"Eddie Chambers [who Klitschko fought last year] was a small heavyweight, and he spent the whole time with Wladimir leaning all over him and he got knocked out in the last round," said the Londoner.
"It takes a strong referee to tell him he can't keep breaking the rules, some are too scared."
Klitschko's trainer, the veteran Emanuel Steward, predicted Haye's biggest problem would not be his charge's size, but rather his speed.
"If Haye thinks he can beat Wladimir for speed, he's in for a big surprise," said Steward, who also trained Lennox Lewis and Thomas Hearns, among many others.
"And Wladimir, for a very tall guy, has great co-ordination, he's very loose and agile. And he has the best one-punch power of any boxer I've ever worked with."
And Vitali Klitschko, the owner of the WBC belt, claimed his younger brother (who has 55 wins and 49 KOs from 58 fights) was superior in every department.
"Look at my brother, he is confident, he trusts himself, he has a lot of experience," said Vitali, who could face Haye if the Englishman wins on Saturday.
"I have some questions for anyone who thinks Haye will win. Is Haye physically stronger than Wladimir? Is Haye faster than Wladimir? Is Haye technically better than Wladimir? Is Haye in better condition than Wladimir? The answer to all those questions is 'no'."