Panzanini competed in her first race at the age of eight. In 1985 she won the Trofeo Topolino . Her breakthrough into world class came in 1991 when she won the giant slalom title and came third in slalom at the Junior World Championships in Geilo, Norway . In 1992 she surprisingly became Italian champion in giant slalom. With these successes behind her, she competed in the Italian World Cup team from the 1992/93 season and celebrated a successful debut right at the start of the season with a second place in the giant slalom in Steamboat Springs .
In the following years Panzanini established himself alongside her teammates Deborah Compagnoni and Karen Putzer in the Italian giant slalom team. Between 1992 and 1997 she won three World Cups and came second five more times. In the 1995/96 season she achieved fourth place in the giant slalom discipline, her best placement in the overall ranking of the World Cup. Two back injuries in 1995 and 1996 as well as a severe leg injury in 1997 interrupted her athletic career.
For her home country she took part in the Winter Olympics twice, in 1994 she finished 15th and in 1998 eighth place in the giant slalom. She took part in four world championships ( 1993 , 1996 , 1997 and 1999 ), but only reached the goal once (fifth place in the giant slalom 1993). After the 1999/2000 season, she withdrew from active competition.