"It was a good day for us, we didn't have anybody in the crash,'' said Jogi Muller, press spokesman for Armstrong's U.S. Postal Service team. ``Our strategy is to stay out of such trouble and keep Lance out of the wind - it was windy out there today.''
AG2R team rider Kirsipuu clocked a time of four hours, 13 minutes and 33 seconds for the 195-kilometer (120.9-mile) trek from Soissons to the Normandy city of Rouen. He crossed the line just ahead of Denmark's Michael Sandstod of CSC-Tiscali and Belgian Ludo Dierckxsens of Lampre.
The victory was Kirsipuu's third in the Tour; he also won stages in 1999 and 2001. In 1999, the year in which Armstrong won his first Tour, Kirsipuu was the only other cyclist to wear the leader's yellow jersey.
"The sprint was really hard because everybody sped up in the last kilometer,'' Kirsipuu told France-2 Television. ``My legs gave out on me, and at the end, it was no longer my abilities as a sprinter that gave me the win, but pure courage.'"
A group of riders suffered a hard crash near the 170 kilometer (105.4 mile) mark, causing Italian rider Marco Pinotti of Lampre to temporarily lose consciousness. He was forced to quit the Tour to receive treatment at a hospital for a broken nose and severe facial bruises.
Lotto's Rik Verbrugghe, who was also involved in the crash, was able to finish the race more than 13 minutes after Kirsipuu. But he was taken to a hospital afterward to be treated for a shoulder injury.
The race got off to a quick start. With several groups pushing the pace as they tried to muster breakaways, the main pack of riders covered 48 kilometers (29.8 miles) in the first hour along the flat course.
"Lance said the first two hours were fast,'' said Muller. ``The team was great. In every major attack early on, there was someone there.''
The main pack of rivals, including overall leader Igor Gonzalez Galdeano of Spain and Armstrong, finished 33 seconds later. Armstrong was in third place in the overall standings, 7 seconds behind Gonzalez Galdeano.
Armstrong is the heavy favorite to win a fourth straight Tour. He plans to keep close to the overall leader the early, flatter stages, then make a move for the lead when the race moves into the mountain stages next week.
Kirsipuu, Sandstod and Dierckxsens were among seven racers who broke away from the main rider pack at the 110-kilometer (68.2-mile) mark. It was the first time in this year's Tour that a small group of breakaway riders kept their lead all the way to the finish line.
Riders passed through a swath of French farmland full of wheat, potato and corn fields. Thousands of fans lined the route, some waving American flags and others holding up signs with words of support for French rider Laurent Jalabert, currently in 15th place and 37 seconds off the pace set by Gonzalez Galdeano. Some fans built a huge statue of a cyclist out of straw.
The course took the 189 riders nearby the burial place of former French Tour champion Jacques Anquetil, one of only four men to win the race five times. It ended along the Seine River in downtown Rouen, capital of the first French region to be liberated entirely by American troops from its Nazi occupiers in World War II.
Thursday's stage marked the first withdrawals so far in the 21-day competition. Belgian champion Tom Steels, who won nine stages in the 1998, 1999 and 2000 Tours, was the first to pull out of the competition after fewer than two hours of racing on Thursday.
As part of its effort to crack down on doping, the International Cycling Union carried out blood tests early Thursday on 34 riders, including Gonzalez Galdeano, from four teams. None of the tests turned up positive.
Friday's sixth stage takes riders on a 199.5-kilometer (123.69-mile) stretch through Normandy from Forges-les-Eaux to Alencon.
Stage 5: Post-stage commentary
Stage 5: Live update summary
Stage 5 results, top 15 (Soissons - Rouen, 195 km):
From the Associated Press
1. Jaan Kirsipuu, Estonia, AG2R, 4 hour, 13 minutes, 33 seconds.
2. Michael Sandstod, Denmark, CSC-Tiscali, same time.
3. Ludo Dierckxsens, Belgium, Lampre, same time.
4. Stefano Casagranda, Italy, Alessio, 3 seconds behind.
5. Christophe Edaleine, France, Jean Delatour, 8 seconds.
6. Robbie McEwen, Australia, Lotto, 33 seconds.
7. Baden Cooke, Australia, FDJeux.com, same time.
8. Stuart O'Grady, Australia, Credit Agricole, same time.
9. Erik Zabel, Germany, Telekom, same time.
10. Andrej Hauptman, Slovenia, Tacconi Sport, same time.
11. Arvis Piziks, Latvia, CSC-Tiscali, same time.
12. Jan Svorada, Czech Republic, Lampre, same time.
13. Nico Mattan, Belgium, Cofidis, same time.
14. Robert Hunter, South Africa, Mapei, same time.
15. Luciano Pagliarini, Brazil, Lampre, same time.
28. Igor Gonzalez Galdeano, Spain, Once, same time.
35. Oscar Sevilla, Spain, Kelme, same time.
37. Lance Armstrong, United States, U.S. Postal Service, same time.
46. Andrei Kivilev, Kazakhstan, Cofidis, same time.
58. Laurent Jalabert, France, CSC-Tiscali, same time.
72. Tyler Hamilton, United States, CSC-Tiscali, 53 seconds.
74. Levi Leipheimer, United States, Rabobank, same time.
80. Joseba Beloki, Spain, Once, same time.
108. David Millar, Britain, Cofidis, same time.
Stage 5 overall standings (top 10):
From the Associated Press
1. Gonzalez Galdeano, 19 hours, 5 minutes, 56 seconds.
2. Beloki, 4 seconds behind.
3. Armstrong, 7 seconds.
4. Jorg Jaksche, Germany, Once, 12 seconds.
5. Abraham Olano, Spain, Once, 22 seconds.
6. Roberto Heras, Spain, U.S. Postal Service, 25 seconds.
7. Isidro Nozal, Spain, Once, 27 seconds.
8. Jose Azevedo, Portugal, Once, 28 seconds.
9. George Hincapie, United States, U.S. Postal Service, same time.
10. Marcos Serrano, Spain, Once, 30 seconds.