Niewiadoma crossed the line in fourth place and broke down in tears as she realised she had done enough to keep the yellow jersey by a margin of just four seconds, with Pauliena Rooijakkers taking second place on the stage and Evita Muzic third.
Vollering (SD-Worx-Protime) began the day eighth overall, one minute and 15 seconds down on Niewiadoma (Canyon–SRAM), but the Dutch rider was expected to be the main danger on the 149.9-km ride from Le Grand-Bornand to Alpe d'Huez.
She crossed the line first but then had the agonising wait for her rival, and Niewiadoma, in a world of pain on the final climb, bravely battled to come in one minute and one second behind Vollering.
Vollering did take an extra 10 seconds for the stage win, but narrowly missed out on what would have been an exceptional comeback after losing the yellow jersey following a crash on stage five.
