The win, before a crowd of 65,080 at Soldier Field, all but clinched a Group A quarter-final berth for the host nation, who meet North Korea in Foxboro tomorrow.
In Portland, Oregon, the North Koreans posted a surprise 3-1 victory over Denmark to keep alive their chance of advancing to the quarter-finals from Group A. Germany picked up their first victory in Group B, crushing Mexico 6-0 at the same venue, with Inka Grings scoring a hat-trick. In Chicago, Brazil clinched a quarter-final berth from Group B with a 2-0 defeat of Italy.
Tiffeny Milbrett led the American onslaught with two goals. Mia Hamm, Michelle Akers, Kristine Lilly and Cindy Parlow added one goal each and Nigeria scored an own goal. The relentless Americans dominated play for long stretches, forcing the Nigerians to commit 29 fouls in a vain attempt to keep the hosts at bay.
"I'm really proud of the way this team handled the physical nature of the game," the US coach, Tony DiCicco, said. "Putting the ball into the back of the net was the best way to slow down a physical team like Nigeria."