Le collet d'allevard -Spaniard Joaquin Rodriguez of Katusha won the sixth stage of the Criterium du Dauphine on Saturday on a breakaway which saw him see off allcomers on the Collet d'Allevard climb.
But Britain's Bradley Wiggins stayed on course for the overall victory after fending off a determined attack from Kazakh veteran Alexandre Vinokourov on the final climb to stay in the yellow jersey.
Rodriguez went for the line on his own five km out and came in with half a minute to spare ahead of Dutchman Robert Gesink, Belgian Jurgen Van den Broeck and Frenchman Christophe Kern.
Vinoklourov placed fifth just ahead of Wiggins, who held off Australian Cadel Evans on the 11.2km final climb to take his lead over Evans to 1min 26sec and 1min 52sec over Vinokourov.
In holding on at the finish at the 1422m Collet d'Allevard the 32-year-old Rodriguez went one better than a series of recent second place finishes which included the Amstel Gold Race and Fleche Wallonne.
The Catalan racer came in fifth in the Tour of Italy but is not intending to race in the Tour de France.
Sunday's final stage is a 117.5km ride from Pontcharra to La Toussuire.
The stage was earlier disrupted in bizarre fashion when two cows on the route caused a mass fall in the peloton some 25km out from the line.
Several riders, including Frenchman Arnold Jeannesson and Spaniard Mikel Landa, came to grief as the two beasts, having escaped from their field, trotted along the road blissfully unaware of the mayhem they had caused.
1. Joaquim Rodriguez Oliver, Spain, Katusha, 5 hours, 12 minutes, 47 seconds.
2. Robert Gesink, Netherlands, Rabobank, 31 seconds back.
3. Jurgen Van Den Broeck, Belgium, Omega Pharma -Lotto, :39 behind
4. Christophe Kern, France, Europcar, :41
5. Alexandre Vinokourov, Kazakhstan, Astana, :50
6. Bradley Wiggins, Britain, Sky, :54
7. Chris Sorensen, Denmark, Saxo Bank, 1:00
8. Jean-Christophe Peraud, France, AG2R La Mondiale, 1:06
9. Cadel Evans, Australia, BMC, 1:09
10. Thomas Voeckler, France, Europcar, 1:58 ^Overall Standings= ^(After 6 of 7 stages)=
1. Bradley Wiggins, Britain, Sky, 23 hours, 16 minutes, 11 seconds.
2. Cadel Evans, Australia, BMC, 1:26 behind
3. Alexandre Vinokourov, Kazakhstan, Astana, 1:52
4. Jurgen Van Den Broeck, Belgium, Omega Pharma-Lotto, 2:13
5. Christophe Kern, France, Europcar, 2:52
6. Joaquim Rodriguez Oliver, Spain, Katusha, 3:01
7. Jean-Christophe Peraud, France, AG2R La Mondiale, 3:30
8. Kanstantsin Sivtsov, Belarus, HTC-Highroad, 4:14
9. Janez Brajkovic, Slovenia, RadioShack, 4:22
10. Thomas Voeckler, France, Europcar, 4:27