Krupp is famous for scoring the memorable Stanley Cup-clinching goal for the Colorado Avalanche in the third overtime period of the fourth game of the 1996 Stanley Cup finals against the Florida Panthers. He later won another Stanley Cup in 2002 as a member of the Detroit Red Wings. However, Krupp missed over 60 games due to a back injury. He did play 8 regular season, and 2 playoff games. He was left off the cup, because he did not qualify. Krupp also scored an overtime goal in the last game of the 1989–90 NHL season as a member of the Buffalo Sabres against the Pittsburgh Penguins that eliminated the Penguins from playoff contention.
In his NHL career, Krupp played 729 games for the Buffalo Sabres, Colorado Avalanche, New York Islanders, Quebec Nordiques, Detroit Red Wings and Atlanta Thrashers before injuries forced him to retire. He then coached the TPHThunder AAA Bantam hockey team.
Krupp was the second German-born player to have a lasting NHL career (Walt Tkaczuk was the first), Krupp was the first German to win a Stanley Cup. He also followed Tkaczuk as the second chosen to an NHL All-Star Game. He was also the largest player in the league for nearly seven years, towering at 6'6". One of the only Cologne-born players to play for the Kölner Haie (Cologne Sharks) of the Deutsche Eishockey League, Krupp was released at age 19 to attempt to earn a spot on the Bowman helmed Buffalo Sabres. Krupp returned to Bowman, years later playing against Detroit Red Wings in the Avalanche's 1996 Stanley Cup run, then as a Wing, in 1998 before injuries sidelined him. After undergoing shoulder reconstruction, back surgery and an undisclosed knee surgery in his final year of play (2003), Krupp finally retired. This was short lived as he was quickly appointed as an Assistant Coach to the German Junior National team. Working up the ranks, he was appointed as an Assistant Coach to the Men's National team under Greg Poss in 2005. Then, shortly before the Torino Olympics, Krupp replaced Poss (who resigned under heavy fire from the German media). Now shortly before the Torino Olympics, Krupp helmed the team elected by his predecessor American. Krupp had strong feelings that the German media never gave Poss his fair chance, using the excuse that Poss was from North America to stonewall any chance Poss may have had of success.
However, Krupp had drastic lineup changes before the World Championship "B-Pool" tournament in store. Facing strong criticism from the German tabloid media, Krupp chose a team of young players, leaving behind seven veterans from the Torino team, in addition to the top goal scorer in the German league. Skewing the team towards youth, he chose players who had led the Junior National team out of the "B-Pool" to lead the Germans past Israel, Hungary, Great Britain, Japan and the home country France. With an unheard of average age of 22, the Germans outscored opponents 35–4 during their four game ascent into the "A" group.
Krupp continued to resist media pressure, maintaining his Atlanta area home, and volunteer coaching position with his son's youth team. Using his North America base, Krupp has brought several young German players to North America for a variety of tournaments and camps, in addition to opening his home to two Hurricane Katrina refugees who played on his son's youth team. Married to an American (dog sled racer Valerie Krupp), he likens himself to German soccer coach, Jürgen Klinsmann, who also resides in the US, married to an American, and schooling his children in an International School. Upon his retirement, Krupp was immediately inducted into the German Hockey Hall of Fame, as a player.