The two-time defending champion Lance Armstrong, meanwhile, opted for a tactical approach as he and other U.S. Postal riders waited for Roberto Heras and Christian Vandevelde after they crashed on a wet course.
Armstrong could have built a big advantage over principal rival Jan Ullrich of Germany, but also knows that he needs all the help from the 2000 Tour of Spain winner Heras in the tough mountain stages next week.
As a result, the day belonged to the French outfit Credit Agricole, which clocked 1 hour 21 minutes 32 seconds for the 67 kilometers from Verdun to Bar le Duc.
"This is great. We have a great atmosphere in the team, that explains our victory," said O'Grady.
ONCE, who had won the team time trial last year, had to settle for second place 31 seconds adrift. Festina were third 54 seconds behind the winners and U.S. Postal finished fourth, 1:26 minutes off the pace.
O'Grady holds the overall leader's yellow jersey after five stages ahead of two teammates. German Jens Voigt rose from fourth to second, 26 seconds behind and Bobby Julich of the U.S. is in third, trailing by 27 seconds.
Armstrong is 15th 1:53 behind and the 1997 winner Ullrich 19th 2:20 adrift. The two had been separated by just four seconds before Thursday's stage.
Ullrich lost 16 seconds less on Armstrong than in last year's team event, but Armstrong's decision to wait for his two crash victims underline the American's huge confidence.
Ullrich's Telekom team arrived with six riders up front, just one more than was needed to stop the clock. Five riders of the nine-men teams have to cross the finish line for the timing, those who trail are personally penalized with the added deficit.
The Tour continues Friday over 211.5km from Commercy to Strasbourg.
Stage 5 results: Verdun-Bar le Duc (67K)
1 Credit Agricole 1.21.32 (49.304 km/h)
2 O.N.C.E.-Eroski, at +0.31
3 Festina, 0.54
4 US Postal Service, 1.26
5 Kelme-Costa Blanca, 1.38
6 Rabobank, 1.47
7 Team Deutsche Telekom, 1.50
8 Cofidis, 2.55
9 Bigmat-Auber 93 2.56
10 Mapei-Quick Step 2.58
11 CSC Tiscali 3.01
12 Bonjour 3.09
13 iBanesto.com 3.45
14 Domo-Farm Frites 3.48
15 Fassa Bortolo 4.01
16 Jean Delatour 4.22
17 Euskaltel-Euskadi 4.45
18 Ag2R Prevoyance 4.52
19 La Francaise Des Jeux 4.58
20 Lotto-Adecco 5.14
21 Lampre-Daikin 5.58
Overall Standings after Stage 5:
1 Stuart O'Grady (AUS), Credit Agricole 20:54:21
2 Jens Voigt (GER), Credit Agricole 0:26
3 Bobby Julich (USA Credit Agricole 0:27
4 Igor Gonzalez De Galdeano (Spa), ONCE-Eroski 0:57
5 Joseba Beloki (Spa), ONCE-Eroski 1.07
6 Carlos Sastre (Spa), ONCE-Eroski 1.08
7 Jrg Jaksche (Ger), ONCE-Eroski 1.12
8 Christophe Moreau (Fra), Festina 1.17
9 Ivan Gutierrez (Spa), ONCE-Eroski 1.20
10 Marcos Serrano (Spa), ONCE-Eroski 1.23
11 Florent Brard (Fra), Festina 1.24
12 Angel Casero (Spa), Festina 1.33
13 Mikel Pradera (Spa), ONCE-Eroski 1.42
14 Luis Perez (Spa), Festina 1.50
15 Lance Armstrong (USA), US Postal Service 1.53
Complete overall standings after Stage 5