Undisputed light heavyweight champion Roy Jones Jr will concede a massive 33lb to WBA heavyweight champion John Ruiz in their title showdown on Saturday.  Stone (bottom left) and Merkerson (right) had to be restrained |
Puerto Rican Ruiz weighed in at 226lb while the 34-year-old Jones tipped the scales at 193lb.
But the weigh-in in Las Vegas was marred by a brawl between Ruiz's manager Norman Stone and Jones' trainer Alton Merkerson.
The incident was sparked by an argument over fight gloves just before the weigh-in took place.
Stone was cut on the lip as punches were thrown and both men fell off the temporary stage.
Stone was stretchered off to hospital complaining of a pain in his side after the weigh-in.
Jones is attempting to become only the second ex-middleweight champion - and the first for over a century - to win a heavyweight title.
The only other man to achieve that feat was Bob Fitzsimmons in 1897.
Jones, whose record is 47-1 with 38 knockouts, last fought in September when he beat British boxer Clinton Woods in a sixth-round technical knockout.
He has won 13 fights in a row since his only defeat, a disqualification against Montell Griffin in March, 1997.
Ruiz's record is 38-4 with one drawn.
The 31-year-old won the WBA title from Evander Holyfield in March 2001.
In his last fight back in July, Ruiz was a narrow winner over Kirk Johnson, who was disqualified in the 10th round for repeated low blows.