In his first full season with the Flyers, Primeau led the team in goals (34) and tied his career-high in points (73). Early in the following season, he was named team captain after defenceman Éric Desjardins resigned from the position. After posting nearly identical seasons statistically in 2001–02 and 2002–03, Primeau was given the task of centering a more defense-oriented line in 2003–04. He did well enough to earn a place in the 2004 NHL All-Star Game, the second of his career. In the 2004 Stanley Cup playoffs, Primeau recorded nine goals and seven assists for a total of 16 points; it was the best playoff year of Primeau's career and his play carried the team to within a game of the Stanley Cup finals. In Game 6 of the Eastern Conference finals, against the Tampa Bay Lightning, Primeau scored the game-tying goal with 1:49 left in regulation. The Flyers won the game, 5–4 in overtime, sending the series back to Tampa for Game 7. The Flyers went on to lose that game by a score of 2–1. Hockey legend Phil Esposito later told Primeau that, "During the '04 playoffs, when you and the Flyers took the Lightning to seven games, you were the most dominating player I ever saw. More than Orr, Howe, Gretzky, or anyone."