Two-time BDO world champion Scott Waites moved into the semi-finals of the 2019 competition with a 5-3 win over fellow Englishman Conan Whitehead.
Ninth seed Waites, 41, a winner in 2013 and 2016, will reach his third final in seven years if he beats 30-year-old fifth seed Michael Unterbuchner.
The German defeated Dutch player Willem Mandigers 5-4 in their quarter-final.
In the women’s event, Japan’s Mikuru Suzuki qualified for the final by beating England’s Maria O’Brien 2-0.
Suzuki, 36, became the first Asian player to reach the women’s final and will meet either English top seed Lorraine Winstanley or three-time champion Anastasia Dobromyslova of Russia.
In the evening session, the last two men’s quarter-finals also take place with reigning champion Glen Durrant playing Kyle McKinstry, the first Northern Irish player to reach the last eight since 1985.
The final match of the day sees Wales’ Jim Williams face England’s Scott Mitchell, the 2015 champion.