Britain's Charlie Edwards will win at least a bronze medal at the European Amateur Championships in Ankara - his first senior international event.
The Croydon 18-year-old came from behind to beat Spain's two-time former European medallist Jose Kelvin de la Nieve 16-13 and reach the semi-finals.
Tom Stalker also reached the semis, beating Armenia's reigning European champion, Hrachik Javakhyan, 13-10.
Wins for Fred Evans and Andrew Selby guarantees four British medals.
Welshman Evans came from behind to pull off a superb win against Russia's Islam Edisultanov, while compatriot Selby booked his third consecutive podium place in the competition, blazing past Frenchman Elie Konki 31-17 in a one-sided flyweight contest.
"It's my first major and I wanted to really go out there and show what I could do," said Evans. "The first two bouts were tough but nothing compared to the Russian, who hit really hard.
"Maybe he knows that I can hit pretty hard too now. It's brilliant to have the medal in the bag but now I'm just thinking of the semi-final on Thursday and going even further."
Selby, from Barry, said he would not be satisfied with a third straight bronze.
"I've had a couple of great bouts and felt really good," he said. "Obviously I've won medals now at three consecutive Europeans which is great, but I won bronzes at the last two and I really want to turn this into silver then gold."
It was a superb performance, meanwhile, from light-flyweight Edwards, who was only promoted to the Great Britain podium programme in May, after winning his first ABA title.
He will next face Azerbaijan's Salman Alizada; all of the semi-finals take place on Thursday.
Liverpool's Stalker, 26, a silver medallist at lightweight last year, showed no ill effects from his recent move up to light-welter, building a second-round lead over Javakhyan and holding it for the final three minutes.
Ray Moylette guaranteed Ireland's first medal with a 14-13 win against Russia's Maksim Ignatiev at welterweight, but there were defeats for John Joe Nevin and Darren O'Neill.
Elsewhere, Luke Campbell suffered a contentious 12-9 loss to Turkey's Furkan Memis.