=2 Andrei Arlovski (11 losses)
Another surprise on this list is former UFC Heavyweight Champion, Andrei Arlovski.
The Belarussian reigned as the top man in the promotion between 2005 and 2006 as he defeated such names as Tim Sylvia, Justin Eilers and Paul Buentello.
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Following his title loss to Sylvia and defeat in a subsequent rematch, Arlovski made it his mission to attempt to regain the gold. An endeavour he is still battling for in 2018.
However, it has proved unsuccessful. Despite winning seven UFC bouts in a row across two spells, Arlovski did not receive another title opportunity and lost an unprecedented five fights in a row to put him firmly at the bottom of the contendership rankings.
Arlovski had a mini reprieve, ending that woeful run with two victories including an impressive win over the giant Stefan Struve, but a further two losses in his most recent fights have increased Arlovski's total defeats in UFC to 11. His career in the organisation could well be over as well as his dreams of becoming a two-time Heavyweight Champion.