The team time trial, only one of which is contested during the three-week competition, was raced over 67.5 kilometers and Armstrong's U.S. Postal team did just what it had hoped to do.
Armstrong's team produced the second-fastest time of the day, ensuring the world's most famous cyclist would not have much time to make up when the tour reaches the mountains next week.
In Wednesday's stage, each of the 21 nine-man teams race as a unit and the time turned in by the team is assigned to each individual member of that team. The clock stops when the fifth member of the team crosses the finish line.
The ONCE team recorded the best time of 1:19.49 with U.S. Postal being clocked in 1:20.05.
Gonzalez Galdeano was the best-placed member of the ONCE team going into Wednesday, having started the day in 12th place, 26 seconds behind front-runner Erik Zabel.
But with the ONCE team finishing more than two minutes ahead of Zabel's German Telekom team, Gonzalez Galdeano leaped to the top of the overall standings. Another ONCE rider, Joseba Beloki of Spain, emerged in second place --- four seconds behind.
Gonzalez Galdeano, who finished fifth overall in last year's tour, is the first Spanish rider in seven years to lead the race.
Since Armstrong has dominated in the mountains and in individual time trials during the last three tours, he is expected to pull away from the field when those stages arrive in the coming days.
"We had a good ride, but apparently others had a better one," Armstrong said. "It's not too bad. We had no accidents, no punctures.
"It was fluid and consistent and I'm content with the team's effort."
France's Laurent Jalabert, who began the day tied with Armstrong for fourth place and 17 seconds out of the lead, seemed destined to take over the yellow jersey that goes to the overall leader when his CSC-Tiscali team had the lead at each of the first two checkpoints.
But his team slowed over the final 20 kilometers and had to settle for the third-fastest time --- 46 seconds behind ONCE and 30 seconds behind U.S. Postal. That left Jalabert 37 seconds behind Gonzalez Galdeano.
After Armstrong in third place, the top 10 was rounded out by Jorg Jaksche of Germany, Abraham Olano of Spain, Roberto Heras of Spain, Isidro Nozal of Spain, Jose Azevedo of Portugal, George Hincapie of the United States and Marcos Serrano of Spain.
The top 14 in the overall standings were from either the ONCE or U.S. Postal teams.
Thursday's stage will be a pack ride of 195 kilometers from Soissons to Rouen.