When they selected him as the first overall draft pick in 1984, the Pittsburgh Penguins hoped that Mario Lemieux would improve the team's fortunes on the ice, and increase interest in the team in the Pittsburgh market. Lemieux, who had scored 133 goals in his final season of junior hockey, recorded his first NHL goal in his first game on his first career shot against the Boston Bruins. On December 31, 1988, Lemieux scored five goals in each of the five different ways possible: even strength, on the power play, short handed, on a penalty shot and into an empty net, a feat no player in league history has duplicated.
Injuries and illness plagued Lemieux throughout his career. He played only 26 regular season games in 1990–91 after surgery to repair a herniated disc in his back, but returned in time to score 44 points in the playoffs in leading the Penguins to their first Stanley Cup. Lemieux continued to struggle with back trouble the next season, though he still won the scoring title, and his second consecutive playoff MVP award in leading the Penguins to their second championship in 1992. In 1993, he was diagnosed with cancer. Lemieux endured 22 radiation treatments in 30 days to treat non-Hodgkin lymphoma. Only 12 hours after his final treatment, Lemieux returned to the Penguins, scoring a goal in his first game back. A second surgery on his back cost Lemieux most of the 1993–94 season, and the entire 1994–95 campaign. As a result of his injuries, Lemieux retired in 1997. He was immediately inducted into the Hockey Hall of Fame; the three-year waiting period was waived by the Hall.
Inspired by his son Austin's desire to see him play, Lemieux returned to the NHL in 2000–01, setting up a goal 33-seconds into his return. He also became the first player-owner in NHL history; he had bought the Penguins in the summer of 1999 to save them from bankruptcy. Lemieux finished the season with 35 goals and 76 points in 43 games. Lemieux continued to battle injuries, missing the majority of the first-half of the 2001–02 season, however he returned to action in time to captain Team Canada to its first gold medal in 50-years at the 2002 Winter Olympics. Injuries again forced his retirement, as Lemieux finally ended his career on January 24, 2006 with 690 goals and 1,723 points in 915 games. Despite his injuries, it has been argued that Lemieux was the greatest player in NHL history. Hall of Famer Bobby Orr claimed Lemieux was the most skilled player he had ever seen, while Mike Gartner said that if he had remained healthy, Lemieux would have scored 1,000 goals.