British boxing hopeful, Frank Arnold, was undefeated at 9-0 heading into his fight with Nicaragua's Brayan Mairena. Mairena landed heavy shots on Arnold that put the young talent down once, before knocking him out cold in the 4th round. Watch the fight highlights now ▶️ Subscribe to BT Sport Boxing on YouTube ➡️ http://www.youtube.com/c/btsportboxing Follow BT Sport Boxing on Twitter ➡️ http://twitter.com/btsportboxing Join our BT Sport Boxing Facebook Group ➡️ https://www.facebook.com/groups/BTSportBoxing/ Follow us on Instagram ➡️ http://instagram.com/btsportboxing Read more on upcoming fights on BT Sport and BT Sport Box Office ➡️ http://www.bt.com/sportboxoffice