WEC 51: Aldo vs. Gamburyan was a mixed martial arts event held by World Extreme Cagefighting that took place on September 30, 2010 at the 1stBank Center in Broomfield, Colorado.

Alex Karalexis was expected to face debuting Chinese prospect Tiequan Zhang at this event, but was removed because of an injury[3] and replaced by UFC veteran Jason Reinhardt.

However, Reinhardt would also be forced from the card after failing a pre-fight eye exam, and was replaced by WEC newcomer Pablo Garza.

[4] The Zhang-Reinhardt matchup would later be rescheduled as a featherweight bout for UFC 127 following the UFC-WEC merger, with Zhang winning by submission.

Clint Godfrey was originally slated to face Demetrious Johnson at this event, but was pulled from the bout due to injury and replaced by WEC newcomer Nick Pace.