UFC lightweight champion Anthony Pettis will make the first defence of his title against Josh Thomson later this year, after number one contender TJ Grant was forced to step aside through injury.

Grant has been slowly working his way back from a concussion suffered in preparing to face Benson Henderson last month, with a delayed timeline for his recovery forcing the UFC to change their plans.

With Grant sidelined Thomson has stepped up to challenge 'Showtime' Pettis, who claimed the strap in some style with a submission win over Henderson.

Thomson will now take on Pettis in the main event of UFC Fight Night on FOX 9, with the bout verbally agreed for December 14 in Sacramento.

'The Punk' earned the chance after emerging victorious from his UFC debut in April, scoring a knockout victory over Nate Diaz with a clinical head kick.

A bantamweight clash between Urijah Faber and Michael McDonald has also been confirmed for the December card, which will be aired on network television in the USA.