After losing his professional debut fight in 2004, Cub Swanson reeled off 11 straight victories, including two in the UFC, before running into former UFC Lightweight Champion Jens Pulver in 2007. After losing to Pulver, Swanson was knocked out by future Featherweight Champion Jose Aldo in one of the most spectacular finishes of 2009, but has since rebounded from the loss. Although his WEC losses have been fast and dominant, Swanson remains one of the most well-rounded fighters in the division, and is considered by many to be the resident gatekeeper toward top contender's status in the promotion. He holds notable career victories over the likes of Charlie Valencia, Micah Miller, Hiroyuki Takaya, and John Franchi.
Swanson would make the move over to the UFC along with many of the WEC fighters. He would lose in his UFC debut by submission to Ricardo Lamas. Swanson would rebound from the loss in spectacular fashion. His first victim was a second round knockout of George Roop. He would follow that win up with back to back Knockout of the Night honors over Ross Pearson and Charles Oliveira moving his way up the rankings to be a serious threat at featherweight.
Swanson was expected to face Dennis Siver at UFC on Fuel TV: Barao vs McDonald. However, Siver was forced out of the bout due to injury, and was replaced by Dustin Poirier. Swanson would win the fight via unanimous decision (29-28, 30-27, 30-27). Swanson would keep his win streak alive when he beat Dennis Siver by TKO in the 3rd round of a Fight of the Night at UFC 162.