Dan Azeez stopped Thomas Faure in the 12th round and Lauren Price beat Naomi Mannes on points as both Britons maintained their unbeaten records.
Light-heavyweight Azeez landed a huge right in the final round of an all-action affair in Paris before the referee intervened.
Azeez, 33, becomes European champion.
Welsh welterweight Price, who won gold at Tokyo 2020, cruised to victory over Germany’s Mannes winning every round on all three judges’ scorecards.
In the main event at Zenith Paris, Cameroon-born heavyweight Carlos Takam beat Frenchman Tony Yoka by split decision.
Two judges scored it 96-94 to Takam, with the other scoring it by the same margin to Yoka.
Azeez targets world title
The European title is the latest accolade for Azeez, who has previously won Southern Area, English, British and Commonwealth titles.
“Step by step I am climbing the ladder,” he said. “British, Commonwealth, European and now it’s the world.”
Both men found success in a competitive first round. Frenchman Faure connected with a right in the second but an Azeez punch bloodied the home fighter’s nose.
Faure landed flush with a right hook in the third, Azeez returning with a right of his own. The Briton continued to stalk and bulldoze his opponent in the fourth.
Each Faure punch was being cheered by the Parisian crowd, but Azeez was landing the cleaner blows. The sixth was a huge round for the Londoner – an overhand right stiffened Faure’s legs and Azeez followed it with a combination of punches to the head.
Faure valiantly held on, but received more punishment in the seventh and eighth. Despite Azeez’s dominance and accuracy, Faure continued to throw punches and may have edged the ninth round.
Azeez outworked Faure in the 10th round. After the 11th his corner instructed him to “go and get it”. A fatigued Faure missed with an uppercut, before Azeez unleashed the right. With Faure still on his feet but clearly hurt, the referee stepped in.
Azeez is just one of the British fighters targeting light-heavyweight gold.
Liverpool’s Callum Smith – a former super-middleweight champion – is mandatory challenger for unified champion Artur Beterbiev’s WBC belt.
Londoner Anthony Yarde lost his challenge against Beterbiev in January, but his spirited display against the Russian star won many fans, while Joshua Buatsi – who won bronze at the 2016 Olympic Games – is also close to world-title contention.
Price shines in Paris
Price, 28, is one of United Kingdom’s most decorated amateurs, having also won gold at the Commonwealth Games, European and World Championships.
The southpaw controlled the opening few rounds, with smart counters and quick hand speed to consistently beat her opponent to the punch.
Mannes is a former European title challenger and had only lost once in seven fights, but Price showed her levels and started to land with ease as the fight progressed.
Price – fighting eight rounds for the first time – landed a stinging body shot in the final round, with all three judges scoring it 80-72 to the winner.
“I felt more comfortable as the rounds went on and felt really good in rounds six and seven,” Price said.
“I am boxing again in October so I wanted to get out. First one is out of the way in 2023. I thought I used my jab very well, but there are things to work on.”