Stoppini started playing tennis when he was eight. He already played a few matches on the ITF Junior Tour and achieved his best placement in 1998 with 77th place.
In the same year he also turned professional and initially tried to make a name for himself on the third-class ITF Future Tour . In 2000 he made his first appearance on the next higher ATP Challenger Tour in Milan . In 2001 he won his first future title and finished the year in the top 500 for the first time in singles and doubles. In 2002 and 2003 he was unable to take part in almost any tournament and lost many places in the world rankings before he was able to improve in 2004 and move into the top 300. This year he made his debut on the ATP World Tour in St. Pölten , where he lost to Ivo Karlović . He also reached his first Challenger final and was in the qualification for the Grand Slam tournament in New York .
Until mid-2010 he played mostly on the Challenger Tour and held his position in the world rankings in singles between 150 and 350th place. Stoppini reached his career high in July 2009 with 161st place, in August 2007 he finished 188th in doubles. The Italian celebrated his greatest success in Washington in 2006 , where he first defeated Paul Goldstein and then defeated former world number one Andre Agassi , who was 22nd in the world at the time. In the quarterfinals he was finally defeated by Mardy Fish . In 2009, his only appearance in a Grand Slam main field followed - in Australia he lost to Novak Đoković in three sets. Before that he had to fight his way through the qualification . He won his only individual title in 2009 in İzmir against Marsel İlhan on the Challenger Tour, and he was three times in a Challenger final: 2004 in Recanati , 2006 in Winnetka and 2008 in Aptos . In doubles he won the Challengers in Cordenons and Lexington each with his compatriot Alessandro Da Col .
From 2011 he lost ground in the world rankings, in mid-2011 he played his last tournament for the time being. In 2012 he returned to the tour for the tournament in Binghamton before ending his career.
Italy
Izmir
Lexington
Olivier Charroin Érik Chvojka