"This game was tremendous," coach April Heinrichs said. "This is a confidence kind of game. If the goals are soft, if your opponent rolls over and dies, then you don't get anything out of it. But I don't think Mexico quit. I can't think of a cheap goal tonight."

Tiffeny Milbrett, who along with MacMillan got most of the cheers from their sparse hometown crowd, added a goal as the Americans cruised to a 4-0 halftime lead. They were never threatened by the smaller, more disorganized Mexican team.

Team USA has won this tournament all six years it has been held, outscoring opponents 87-8 in 19 games.

The game was the first for the United States since it opened residency camp in California three weeks ago. The Americans' last game was a 0-0 tie with Iceland in Charlotte, N.C., on April 8. Their last win came three days earlier, 8-0 over Iceland.

"Our job is to get the younger players to meld in with us," MacMillan said. "Just in the last few weeks, the team is already looking great. Everyone is stepping up, and the competitiveness we had in camp has just been tremendous. It's making everybody a better player for it."

Exploiting a considerable advantage in quickness, seven players scored for the Americans, including Kristine Lilly, who extended her world record by playing in her 199th international game for the U.S. team.

Lilly, who played her first game with the national squad in 1987 at the age of 16, will reach 200 caps if she plays in Sunday's championship against Canada. The closest player to Lilly -- man or woman -- is Hamm, who has 190 appearances.

Young U.S. goalkeepers Siri Mullinix and Hope Solo, an 18-year-old freshman at the University of Washington, combined for the shutout in place of starter Briana Scurry, who is sitting out the tournament with a thigh injury.

One of those newcomers likely will make the 18-player roster for the Olympics in Sydney. Assuming Heinrichs selects the 15 returning World Cup players she invited to residency camp, that leaves two open spots in the field.

MacMillan opened the scoring on a penalty kick in just the third minute. Hamm was brought down from behind by Fabiola Vargas to draw the penalty.

Lilly dribbled past a defender and fired a shot into the left corner of the goal for a 2-0 lead in the 22nd minute.

Nikki Serlenga, playing in just her fourth game, scored her second international goal -- a powerful shot high into the net -- in the 25th minute to push the lead to 3-0.

U.S. forward Christie Pearce (left) tries to steal the ball from Mexico's Maribel Dominguez.(AP)

"They're going to follow Mia out or Lil, which gives me a lot of space," said the 21-year-old Serlenga. "Those girls, they make the space for us."

Lorrie Fair, 21, and Christie Welsh, 19, also scored goals for the Americans. Welsh has six goals in nine games.

Milbrett rebounded her own shot off Mexican keeper Linnea Quinonez for a 4-0 lead. Milbrett has scored in each of the United States' four games played in Portland.

MacMillan had the goal of the night in the second half. On a perfect cross from Sara Whalen, MacMillan came rushing in and punched the ball in with a knee in the 61st minute for a 6-0 lead.

"Coming off the Iceland game, we had some fury in us," MacMillan said. "We wanted to come after them, and we kept the rhythm of the game going. The dynamic pace that we set, we definitely got a lot out of it."

Despite the draw of the Mexican team on Cinqo de Mayo, only 6,517 fans braved the chill to watch both games at Civic Stadium. A crowd of 23,325 turned out for Team USA's "send-off" match for the World Cup last summer.

Canada defeated South Korea 1-0 earlier in the night.