Kevin Korjus scored his first-ever GP3 Series pole position at Silverstone on Saturday morning for Koiranen.
Korjus lapped in 1m46.360s in the closing moments of a thrilling qualifying session, pipping home hero Jack Harvey of ART by just 0.055 seconds. Pole changed hands countless times during the half-hour session.
The second ART car of Facu Regalia will start third, ahead of Alex Fontana. Carlos Sainz Jr. was fifth fastest, and will start alongside points leader Tio Ellinas.
Daniil Kvyat set the fastest middle sector time but wound up down in seventh, from the second British racer on the grid Nick Yelloly, who went off at Abbey on his final effort.
Valencia race winner Conor Daly will start ninth, ahead of Patric Niederhauser and Aaro Vainio. The other Valencia winner, Robert Visoiu, was 14th.