The Olympic champion has yet to drop a game in the tournament in the Ukrainian capital as she proved too strong for Turkish fifth seed Neslihan Yiğit.

There was little separating the two players in the first game, but Marin crucially came out on top before powering home to complete a 21-18 21-9 triumph.

Marín secured the European crown in 2014, 2016, 2017 and 2018 but she will need to overcome Danish sixth seed Line Christophersen to extend that winning streak.

Christophersen came through a three-game battle as she edged out Scottish fourth seed Kirsty Gilmour 21-13 7-21 21-10.

"It was all about getting the initiative and the attack," said Christophersen.

"I am happy that I came out aggressive in the third game, and now I am just happy and proud that I will be playing tomorrow."

Gilmour added: "We both had to put absolutely everything into it.

"It was a big contrast from yesterday’s match [against Lianne Tan] and considering that I had three or four weeks of pain-free training, I am disappointed, but it is still a European medal."

There is scheduled to be an all-Danish men’s singles final after Viktor Axelsen and Anders Antonsen both secured straight game victories, although that is now in doubt as it was announced following Axelsen's win against Kalle Koljonen that the top seed had tested positive for coronavirus.

A second PCR test is scheduled this evening with the result due to come through in the morning.

"An amazing badminton day just became very dark here in Kyiv - no one wanted this to happen, and all we can do is to hope for a negative test answer on the second test, although it is unlikely," said Badminton Europe deputy general secretary Jimmy Andersen.

Earlier on the court, Axelsen beat Koljonen 21-14 21-14 triumph while Antonsen defeated compatriot Hans-Kristian Solberg Vittinghus 21-14 21-17.

The mixed doubles final will see top seeds Marcus Ellis and Lauren Smith of England face Russian sixth seeds Rodion Alimov and Alina Davletova.

Ellis and Smith defeated Denmark’s Mathias Christiansen and Alexandra Bøje 21-17 21-19, while Alimov and Davletova saw off Germans Mark Lamsfuss and Isabel Herttrich 21-8 21-12.

Women’s doubles top seeds Gabriela Stoeva and Stefani Stoeva remain on track to defending their title after the Bulgarians beat Danish third seeds Maiken Fruergaard and Sara Thygesen 21-16 21-10.

The Stoeva sisters will now face second seeds Chloe Birch and Lauren Smith of England who triumphed 21-18 21-16 against Dutch fourth seeds Selena Piek and Cheryl Seinen.

In the men's doubles top seeds Kim Astrup and Anders Skaarup Rasmussen of Denmark were defeated in two tight games by fifth seeds Mark Lamsfuss and Marvin Seidel of Germany 23-21 21-17.

Lamsfuss and Seidel will face third seeds Vladimir Ivanov and Ivan Sozonov of Russia who defeated second seeds Marcus Ellis and Chris Langridge of England 21-15 21-10.