Team Sky's Bradley Wiggins lost his Tour de Romandie lead after Spain's Luis Leon Sanchez claimed Saturday's fourth stage from Bulle to Sion.
Sanchez, riding for Rabobank, won his second consecutive stage to earn a 10-second time bonus that lifted him above Wiggins, who was awarded the same time.
Sunday's 16.5km Crans-Montana time trial will now decider the winner.
"It's not a bad position to be in going into the time trial," said Team Sky sports director Sean Yates.
Wiggins, who is the world time trial silver medallist, led Sanchez by just one second going into the 184km fourth stage.
His Team Sky team-mates Mark Cavendish and Geraint Thomas, who won the Swiss tour's opening prologue, did much of the work on the front of the peloton to keep a six-man breakaway in check.
The British duo had dropped away before the final two category one climbs of the day, but Wiggins, who turned 32 on Saturday, remained near the front and was in a 12-man group on the final descent into Sion.
He was joined by team-mates Richie Porte and Michael Rogers for the run-in but Rabobank also had riders in the leading group and they delivered a victory for Sanchez ahead of AG2R La Mondiale's Rinaldo Nocentini, with Branislau Samoilau third for Movistar.
"It was a fantastic display [by the team], possibly the best I've seen," added Yates.
"Every single one of them did their role perfectly, starting with Cav and G on a hellishly windy section up the valley earlier on.
"All the other guys then did their bit to a 'T'; other teams tried to throw everything at us but we controlled it so well and I think we'll have earned plenty more respect."