[1] Diekmann had one amateur fight against future UFC competitor Sean Gannon, a Boston police officer best known for defeating Kimbo Slice in non-sanctioned bout.
Diekmann later turned professional in 2005, he won his first six bouts by stoppage before losing to Justin Eilers via TKO at WEC 24.
The following October, Diekmann was defeated by Tyler King via unanimous decision at CES MMA: Real Pain.
Diekmann got his first win for the promotion when he defeated Chris Guillen via first-round TKO at CES MMA: November to Remember.
Instead, Diekmann faced Manny Lara and the fight ended in a no contest due to an accidental eye poke in round one.