Summary

First round
The World Cup started with a shock 1-0 defeat of defending champions France, playing without the injured Zinedine Zidane, by tournament newcomers Senegal in the tournament's opening match held in Seoul, Korea. In their second Group A game, France were held to a goalless draw by Uruguay after star striker Thierry Henry was sent off. A 2-0 defeat by Denmark in their last group game sealed France's fate. The world champions went out of the Cup without even managing to score a goal and earned the unwanted record of the worst World Cup performance by a defending champion. An impressive Denmark won the group, joined by Senegal to move on to the next round. Senegal drew with Denmark and Uruguay to clinch its place in the second round. Despite coming back from 0-3 to tie Senegal in their last group game, the South Americans couldn't find the fourth goal that might have kept them in the Cup and thus were out of the tournament.

2002 World Cup mascots
Spain became one of only two teams to pick up maximum points in the Group B, seeing off both Paraguay and Slovenia 3-1 before beating South Africa 3-2. Paraguay needed a late goal against another newcomer, Slovenia, to tie South Africa on goal difference (they were already tied on points) and move to the second round on the next tiebreaker, goals scored.
The other team to win all their group games was Brazil in Group C. Turkey advanced to the next round, too, beating Costa Rica on goal difference. China, coached by Bora Milutinović (the fifth national team he coached in five consecutive World Cups), failed to get a point or even score a goal.
Group D saw several surprises as the United States beat Portugal, who many had tipped to win the tournament, 3-2. Then, goalkeeping by Brad Friedel earned the Americans a 1-1 draw with South Korea. South Korea, which previously beat Poland 2-0, beat Portugal in the deciding third match to send the Europeans home and also give the United States a ticket into the second round, despite losing to Poland in the 3rd match.
Germany thrashed Saudi Arabia 8-0 in Group E thanks to three goals from Miroslav Klose. Ireland were playing without captain Roy Keane, sent home days before the World Cup, but led by his unrelated namesake Robbie claimed second place at the expense of African champions Cameroon.
Other than France's failures, the biggest shock of the tournament came in the Group of Death, Group F as pre-tournament favorites Argentina failed to move out of the group. A loss to England 1-0 on a David Beckham penalty and a subsequent draw with Sweden kept the South Americans from advancing. The Scandinavians won the group, with England also going through. Nigeria finished last.
In Group G, Italy, Croatia, and Ecuador all beat each other once. But the Italians' draw against group winners Mexico, while the other two lost to the North Americans, gave the three-time World Cup champions second place in the group. Ecuador could still enjoy a victory on their first World Cup, beating Croatia 1-0.
Co-hosts Japan breezed through Group H, joined by Belgium. Russia and Tunisia were two of the disappointments of the tournament, in what was considered the weakest group of the tournament.