Michael Woods of Israel Start-Up Nation won Saturday's queen stage in the Tour de Romandie as Geraint Thomas crashed in the final metres to let victory slip away.
Experienced Canadian Woods edged Australian Ben O'Connor of AG2R Citroen to win stage four, while 2018 Tour de France winner Thomas of Ineos fell in the battle to the line to finish third.
As the leaders approached the ski-station finish in Thyon at the end of the final climb on a mountainous 161.3 km ride from Syon, Welshman Thomas drove for the line but lost his grip on his handlebars and fell.
"To deck it there, I feel like a right whopper," Thomas said.
Woods overtook and crossed the line, celebrating victory and grabbing the overall lead, while Thomas was still climbing back on his bike, having missed a chance of taking the stage and control of the race.
"I had no feeling whatsoever in my hands and I tried to change gear but instead I just lost the bars," Thomas said.
"It's so frustrating because even if I had just stayed in that gear and just come second."
"I just want to win a stage."
Woods leads Thomas by 11 seconds ahead of the final stage, a 16.2km time trial around Freiburg on Sunday.
Spaniard Marc Soler, the race leader before the start of this fourth stage, slipped to fourth, 33 seconds behind Woods.