NANTES, FRANCE, JULY 2 -- Former world cycling champion Moreno Argentin of Italy won the third stage of the Tour de France today after a protest by farmers forced organizers to re-route the race.

Argentin, the 1986 world champion, displayed the form that already has won him two classics this season as he made a powerful move 20 miles from the line and pedaled home 2 minutes 29 seconds ahead of the pack. Argentin did it despite deep bruises to his right thigh, caused by one of many spills during heavy rain.

Canada's Steve Bauer, who had taken a 10-second lead over the main favorites Sunday, retained the overall lead.

An unlikely hero of the stage from Poitiers to Nantes, in western France, was a 16-year-old local boy named Michael.

Tour organizers were forced to change the stage's route after 54 miles to avoid a demonstration by angry sheep farmers, who chopped down trees and spread manure across the road. The farmers used the race to highlight their complaints over low prices for mutton.

Michael came to the rescue, opening a way through small country roads near Bressuire for the 198 riders and hundreds of motorcycles and press cars on the Tour.

The detour added three miles to the 142.6-mile stage, completed by Argentin in 5 hours 46 minutes 13 seconds. Argentin, current leader in the World Cup, came in ahead of Frenchman Christophe Lavainne and East German Uwe Raab. He is fifth overall, 8 minutes 23 seconds behind Bauer. Frans Maassen of the Netherlands is second overall, eight seconds back.

The pack, burned by Bauer's breakaway Sunday, managed to foil the numerous similar attempts until Argentin tried his luck 20 miles out.

"Above all I wanted to get rid of the sprinters," he said.

THIRD STAGE RESULTS

At Nantes, France

144.5-mile leg from Poitiers to Nantes

1, Moreno Argentin, Ariostea, Italy, 5 hours 46 minutes 13 seconds; 2, Christophe Lavainne, Castorama, France, 2:29 behind; 3, Uwe Raab, PDM, East Germany, same time; 4, Olaf Ludwig, Panasonic, East Germany, same time; 5, Johan Capiot, TVM, Belgium, same time; 6, Sean Kelly, PDM, Ireland, same time; 7, Jelle Nijdam, Buckler, Netherlands, same time; 8, Soren Lilholt, Histor, Denmark, same time; 9, Asiate Saitov, Alfa, Soviet Union, same time; 10, Marc Sergeant, Panasonic, Belgium, same time; 11, Henri Manders, Helvetia, Netherlands, same time; 12, Andreas Kappes, Toshiba, West Germany, same time; 13, Adriano Baffi, Ariostea, Italy, same time; 14, Christian Chaubet, Toshiba, France, same time; 15, Mathieu Hermans, Seur, Netherlands, same time.

Other Americans and 7-Eleven Members

22, Davis Phinney, 7-Eleven, Boulder, Colo., 2:29 behind; 27, Andy Bishop, 7-Eleven, Tucson, same time; 36, Steve Bauer, 7-Eleven, Canada, same time; 37, Greg LeMond, Z, Wayzata, Minn., same time; 47, Sean Yates, 7-Eleven, Britain, same time; 74, Bob Roll, 7-Eleven, Pleasant Hill, Calif., same time; 81, Ron Kiefel, 7-Eleven, Boulder, Colo., same time; 104, Andy Hampsten, 7-Eleven, Boulder, Colo., same time; 122, Dag-Otto Lauritzen, 7-Eleven, Norway, same time; 142, Norman Alvis, 7-Eleven, Sacramento, Calif., same time.

Overall Standings

(After three stages)

1, Steve Bauer, 7-Eleven, Canada, 10 hours 9 minutes 55 seconds; 2, Frans Maassen, Buckler, Netherlands, 8 seconds behind; 3, Ronan Pensec, Z, France, 26 seconds; 4, Claudio Chiapucci, Carrera, Italy, 50 seconds; 5, Moreno Argentin, Ariostea, Italy, 8:23; 6, Raul Alcala, PDM, Mexico, 9:47; 7, Vintyeslav Ekimov, Panasonic, Soviet Union, 9:49; 8, Steven Rooks, Panasonic, Netherlands, 10:01; 9, Sean Kelly, PDM, Ireland, same time; 10, Eric Van Lancker, Panasonic, Belgium, 10:03; 11, Alan Peiper, Panasonic, Australia, same time; 12, Guy Nulens, Panasonic, Belgium, same time; 13, Eric Breukink, PDM, Netherlands, 10:06; 14, Marc Sergeant, Panasonic, Belgium, same time; 15, Thierry Marie, Castorama, France, 10:09.

Other Americans and 7-Eleven Members

35, LeMond, 10:33 behind; 48, Yates, 10:52; 53, Lauritzen, 10:59; 56, Hampsten, 11:02; 58, Kiefel, 11:04; 60, Bishop, 11:09; 62, Alvis, 11:10; 65, Roll, 11:12; 83, Phinney, 11:27.