Brian Nielsen (born 1 April 1965) is a Danish former professional boxer. He held the International Boxing Organization (IBO) heavyweight title from 1996 to 1999 successfully defending it five times, including against Larry Holmes and Phil Jackson. He equalled Rocky Marciano's record of 49 successive wins with no losses when he stopped Tim Witherspoon in the fourth round on 16th April 1999 in the K.B. Hallen, Copenhagen, Denmark.

On 13 October 2001, Nielsen fought Mike Tyson at the Parken Stadium in Copenhagen. After six rounds heavily in Tyson's favour, Nielsen quit on his stool citing an eye injury. Nielsen was knocked down once in the third round. He finished his career with 64 wins and three defeats.

Tim Witherspoon (born December 27, 1957) is an American former professional boxer who competed from 1979 to 2003. He was a two-time world heavyweight champion, having held the World Boxing Council (WBC) title in 1984, and the World Boxing Association (WBA) title in 1986. He beat Heavyweight World Champions Greg Page, James Smith, Tony Tubbs, Frank Bruno and Cruiserweight World Champions Alfonzo Ratliff and Al Cole. He is best known for his fight against undefeated Heavyweight World Champion Larry Holmes in which he lost by Split decision. Witherspoon also worked as a regular sparring partner for Muhammad Ali.

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