Yates, 26, trailed Astana's Fuglsang by eight seconds before stage eight, but was keeping pace with his rivals when he withdrew with less than 50km to go.

Team Ineos' Dylan van Baarle won the 113.5km stage from Cluses in France to Champery in Switzerland.

Fuglsang finished 20 seconds ahead of American Tejay van Garderen in second.

Swiss-born Fuglsang, 34, also won the Dauphine in 2017.

Van Baarle clinched the stage win in a sprint finish with Mitchelton-Scott's Jack Haig, who went solo with 16km remaining before the Dutchman soon joined him.

Mitchelton-Scott sports director Lorenzo Lapage told race organisers that Yates, who is due to lead the team at the Tour de France in July, was struggling with a fever since Sunday morning.

He wore the leader's yellow jersey for four stages until Fuglsang claimed it on Saturday.

Stage eight results

1. Dylan van Baarle (Ned/Team Ineos) 3hrs 5mins 48secs

2. Jack Haig (Aus/Mitchelton-Scott) same time

3. Carl Fredrik Hagen (Nor/Lotto-Soudal) +50secs

4. Warren Barguil (Fra/Arkea-Samsic) +1min 12secs

5. Sepp Kuss (US/Jumbo-Visma) same time

6. Sebastien Reichenbach (Sui/Groupama-FDJ)

7. Julian Alaphilippe (Fra/Deceuninck-Quick-Step) +1min 16secs

8. Alexey Lutsenko (Kaz/Astana Pro Team) +1min 59secs

9. Xandro Meurisse (Bel/Wanty-Gobert Cycling) same time

10. Emanuel Buchmann (Ger/Bora-Hansgrohe) same time

General classification

1. Jakob Fuglsang (Den/Astana Pro Team) 30hours 44mins 27secs

2. Tejay van Garderen (US/EF Education First) +20secs

3. Emanuel Buchmann (Ger/Bora-Hansgrohe) +21secs

4. Wout Poels (Ned/Team INEOS) +28secs

5. Thibaut Pinot (Fra/Groupama-FDJ) +33secs

6. Dylan Teuns (Bel/Bahrain-Merida) +1min 11secs

7. Alexey Lutsenko (Kaz/Astana Pro Team) +1min 12secs

8. Daniel Martin (Ire/Emirates) +1min 21secs

9. Nairo Quintana (Col/Movistar) +1min 24secs

10. Romain Bardet (Fra/AG2R La Mondiale) +1min 38secs