L'Alpe d'Huez - Australian Richie Porte of the BMC team turned the screws on Chris Froome in Saturday's seventh stage of the Criterium du Dauphine won by the latter's Team Sky team-mate Peter Kennaugh.
With just one stage to go on Sunday, Porte spurted at the end of a gruelling day's racing to gain valuable seconds on direct rivals for the overall race victory, putting a further 23 seconds between himself and former team-mate Froome, in second at 1:02.
Defending champion Froome, a three-time winner of the Tour de France, couldn't stick with Porte's acceleration on the last 2km of the 168km ride from Aosta to the epic Alpe d'Huez climb and summit finish via the Col de Sarenne.
Astana's Danish rider Jakob Fuglsang, a silver medallist in the road race event at last year's Rio Olympics, did manage to tail Porte and now stands third in the overall classification, at 1:15.
Froome's Team Sky teammate Kennaugh, who won gold as part of the British team pursuit team at the 2012 Olympics, soloed to the stage win after pulling away from British compatriot Ben Swift (UAE Team Emirates) in the final three kilometres.
Sunday's eighth and final stage is another testing mountain ride, 115km long over three cols (Saisies, Aravis, Colombiere) before a final climb to the finish line at the Plateau de Solaison, high in the Alps.
Results and standings after the seventh stage of the Criterium du Dauphine on Saturday, a 168km ride from Aosta to Alpe d'Huez:
1. Peter Kennaugh (GBR/SKY) 4hr 43min 59sec, 2. Ben Swift (GBR/EAU) at 13sec, 3. Jesus Herrada (ESP/MOV) 1:11, 4. Jelle Vanendert (BEL/LOT) 1:13, 5. Romain Bardet (FRA/ALM) 1:14, 6. Richie Porte (AUS/BMC) 1:56, 7. Jakob Fuglsang (DEN/AST) 1:56, 8. Andrew Talansky (USA/CAN) 2:04, 9. Alberto Contador (ESP/TRE) 2:04, 10. Fabio Aru (ITA/AST) 2:13
15. Chris Froome (GBR/SKY) 2:19.
20. Esteban Chaves (COL/ORI) 2:42.
1. Richie Porte (AUS/BMC) 25hr 38min 29sec, 2. Christopher Froome (GBR/SKY) at 1min 02sec, 3. Jakob Fuglsang (DEN/AST) 1:15, 4. Fabio Aru (ITA/AST) 1:41, 5. Alejandro Valverde (ESP/MOV) 1:43, 6. Alberto Contador (ESP/TRE) 1:55, 7. Romain Bardet (FRA/ALM) 2:07, 8. Dan Martin (IRL/QST) 2:31, 9. Emanuel Buchmann (GER/BOR) 2:53, 10. Andrew Talansky (USA/CAN) 3:43