LAS VEGAS -- Tonight’s UFC 213 card has lost its main event.

UFC women’s bantamweight champion Amanda Nunes was forced to withdraw from her title fight against Valentina Shevchenko Saturday morning after falling ill and being transported to the hospital, MMA Fighting has learned.

As a result, the Yoel Romero vs. Robert Whittaker interim middleweight title fight will serve as the new UFC 213 main event.

Nunes (14-4) won the bantamweight title last July when she defeated then-champion Miesha Tate. Amazingly, that fight served as the UFC 200 main event after Jon Jones failed a pre-fight drug test and was pulled from the card just days before.

Nunes beat Shevchenko via unanimous decision in March 2016 at UFC 196.

UFC 213, which takes place at the T-Mobile Arena in Las Vegas, will now proceed with 11 fights. Due to the late switch, the UFC is obligated to offer refunds to any ticket purchasers who seek them, per Nevada Athletic Commission rules.