Ghana-born Joshua Buatsi extended his pro record to 5-0 after beating 52-fight veteran Bartlomiej Grafka in Cardiff on Saturday night.
The 2016 Team GB Olympic standout cruised to a six-round decision on the undercard to Anthony Joshua vs Joseph Parker.
Buatsi was in control throughout and badly damaged his experienced opponent's face but was made to settle for a points victory, decided 60-54 in his favour by the referee.
Grafka was down early, but it wasn't ruled a knock-down, and he soon became target practice for the calm Buatsi.
The London prospect head-hunted for a stoppage towards the end of the first round and, in the second, impressed with his inside-fighting although he berated himself when caught by a clumsy punch.
A fifth-round uppercut from Buatsi was the best punch of the fight, serving to wobble his opponent's legs, but Grafka was a tough nut to crack.
It was Buatsi's second fight at the Principality Stadium, having also featured on Joshua's undercard last October.
Joshua Buatsi, has lived in Croydon since his family moved from Ghana to England when he was aged nine.