B*Witched and Billie performed at the opening ceremony for the Women's World Cup at Giants Stadium; Billie's single, "Because We Want To", was chosen as the tournament's official song. Pop singer Jennifer Lopez performed at the closing ceremony before the final and also recorded an official music video for her single "Let's Get Loud". Group stage The sixteen participating teams were organized into four groups, labeled A to D, by the final draw on February 14, 1999. The group stage consisted of 24 matches played in a round-robin format, in which each team played one match against the other three in their group. Teams were awarded three points for a win, one point for a draw, and none for a defeat. The winners and runners-up from each group qualified for the first round of the knockout stage, which began with the quarter-finals on June 30, 1999. Group A Hosts and 1991 champions United States were placed in Group A alongside Denmark, who were undefeated in European qualification, Nigeria, champions of the African qualifying competition, and North Korea in their World Cup debut. The United States defeated Denmark 3–0 in the opening match, played on June 19 in front of a record 78,972 at Giants Stadium, with goals scored by Mia Hamm, Julie Foudy, and Kristine Lilly. The following day at the Rose Bowl, North Korea lost 2–1 to Nigeria by conceding goals to Mercy Akide and Rita Nwadike in the second half. The United States hosted Nigeria at Chicago's Soldier Field for their second match. They fell behind in the second minute by conceding a goal to Nkiru Okosieme after a defensive mistake. The Americans rallied and found an equalizer in the form of an own goal scored by Ifeanyi Chiejine in the 19th minute. This initiated a 23-minute period where the home side scored six goals on their way to a 7–1 victory. North Korea earned an upset victory over Denmark in Portland, winning 3–1 with two first-half goals and another in the 73rd minute before a consolation goal by the Danes. The North Korean victory denied the United States an instant berth in the quarter-finals. It also preserved the chances for all four teams in the group to finish in the top two places and qualify for the knockout stage. Nigeria became the first African team to advance to the quarter-finals of a Women's World Cup with a