The 2002 World Cup was the high point of Arena's career as the U.S. coach. Heavy underdogs coming into the tournament, they stunned the world by beating a respected Portuguese team 3–2 in their opening game. Arena was lauded afterward for instilling in his players the confidence to play aggressively against an international powerhouse. A hard-fought tie against host nation South Korea was enough to qualify for the second round, despite a poor loss against Poland in the final group game. Arena and the U.S. met old nemesis Mexico in the Round of 16, and Arena adapted his tactics to secure a 2–0 victory and a quarterfinal berth. The U.S. switched from their usual 4–4–2 to a 3–5–2, and it paid dividends almost immediately when Josh Wolff, who Arena had brought in to fill out the formation, set up Brian McBride for the winning goal early in the first half. Arena switched the team back to a 4–4–2 for their quarterfinal against Germany, and the team continued to surprise many by dominating stretches of the game. However, they lost 1–0 on a Michael Ballack header.