Liverpool middleweight Anthony Fowler upset Ukrainian second seed Dmytro Mytrofanov to march into the quarter-finals of the World Championships in Almaty on Monday.
Fowler produced one of the finest performances of his career to claim a unanimous verdict over the powerful second seed, who had stopped Olympic silver medallist Fred Evans in a World Series of Boxing bout in London in May.
Fowler will now face Germany's Stefan Haertel - who beat him in the last 16 of the European Championships in Minsk in June - in the quarter-finals when a guaranteed medal will be at stake.
Ireland's reigning European champion Jason Quigley also reached the middleweight quarter-finals with a unanimous victory over gutsy Scot Aston Brown.
In his debut at bantamweight, Olympic bronze medallist Michael Conlan set up a last-eight meeting with Russia's Vladimir Nikitin after a unanimous win over Brian Gonzalez of Mexico.
And another excellent day for Ireland was complete when heavyweight Tommy McCarthy also made it into the quarter-finals with a 3-0 win over Emir Ahmatovic of Germany.