Membrado began the day 10.0sec ahead of Tymek Abramowski, but saw that advantage reduced to only 4.4sec on the opening Parkkola test.
A broken brake disc for Abramowski on the following stage handed Membrado breathing room, however, and nobody came within 15sec of his Ford Fiesta Rally3 over the remainder of the day.
Abramowski’s problems dropped him to third as reigning champion Matteo Fontana continued his recovery from the time lost during a mid-stage wheel change on Friday.
Kerem Kazaz began Saturday’s final test poised to challenge for a podium position, sitting just 16.6sec behind Abramowski. However, a puncture cost the Turkish driver more than 1min 15sec and dropped him from fourth to fifth.
That promoted Jarkko Nikara, co-driven by Toyota Gazoo Racing WRC Challenge Programme co-driver Tomiya Maekawa, into fourth.
Finnish drivers Ville Pynnönen and Riku Tahko completed the day sixth and seventh respectively, one place ahead of Ali Türkkan.
Türkkan stopped to change a wheel on SS12, further hampering his hopes of climbing the order after losing more than three minutes when he went off the road on Friday.
Earlier in the day, Bolivian Nataniel Bruun retired 10.7km into the opening stage with a transmission problem.
Toyota Gazoo Racing WRC Challenge Programme driver Kanta Yanaguida did not restart following his crash aboard a Renault Clio Rally3 on Friday.