• 2001: World Natural Championships - UIBBN, Light-MiddleWeight, 4th
• 2002: World Natural Championships - UIBBN, MiddleWeight, 9th
• 2003: European Championships - WABBA, Short, 7th
• 2003: World Championships - WABBA, Short, 3rd
• 2004: World Championships - WABBA, Short, 4th
• 2005: World Championships - WABBA, Short, 2nd
• 2007: IFBB Belgian National Championships - Overall
• 2008: Europa Supershow - IFBB, Open,
• 2008: Tampa Bay Pro - IFBB, Open,
• 2009: Tampa Bay Pro - IFBB, Open, 14th
• 2009: Atlantic City Pro - IFBB, 202 class, 3rd
• 2009: Mr. Olympia - IFBB, 202 class, 13th
• 2010: Tampa Pro - IFBB, 202 class, 6th
• 2010: Dallas Pro - IFBB, 202 class, 7th

  
  

In 2009, Clarence hit 282 pounds in the 2009 offseason