Gross comes from Pozza di Fassa in the Fassa Valley . He drove his first FIS race in January 2002. In 2003 and 2004 he achieved second place in slalom at the Italian Junior Championships. In 2005 he took part in a junior world championship for the first time . He had his first start in the European Cup in December 2005, but did not achieve any results worth mentioning for the time being. At the junior world championship in 2006 he finished fourth in slalom, a little later he became Italian slalom junior champion. He made his debut in the World Cup on December 22, 2008 in the slalom of Alta Badia . On February 1, 2009 he reached the points for the first time with rank 25 in the slalom of Garmisch-Partenkirchen .
In the European Cup at the end of the 2008/09 season , Gross took eighth place in the slalom in Crans-Montana, his first top 10 position and on January 22nd, 2010 he made it onto the podium for the first time with second place in the slalom in Bansko . With another two podium places he reached fourth place in the slalom classification in the 2009/10 European Cup season . His only World Cup result in the 2009/10 season was a 21st place in the slalom of Kranjska Gora on January 31, 2010. In the 2010/11 season he was able to score in three World Cup slaloms. At the 2011 World Championships in Garmisch-Partenkirchen, he finished 22nd in slalom.
In the 2011/12 season Gross advanced to the world's top slalom. He achieved his first top 10 result in the World Cup on December 19, 2011 with rank 8 in Alta Badia. On January 8, 2012, he finished 3rd in Adelboden and achieved his first World Cup podium. There was also a second place in Schladming and a third place in Bansko , which resulted in fifth place in the slalom discipline. Gross could not quite maintain this level in the 2012/13 season : Four times he was among the top ten, a fourth place was his best result. Three more top 10 placements were added in the 2013/14 season. His best ranking at a major event was fourth place in the slalom of the 2014 Winter Olympics in Sochi , where he was only five hundredths of a second short of the bronze medal.
After a somewhat subdued start to the 2014/15 season , Gross won somewhat surprisingly in Adelboden on January 11, 2015 , leaving Fritz Dopfer by two and Marcel Hirscher by three hundredths of a second behind. To this day, this has been his only World Cup victory. He confirmed his good form with a second place each in Wengen and Schladming. Three third places were added in the 2015/16 season : at the slaloms in Wengen and Kranjska Gora and at the City Event in Stockholm . Gross stood on a slalom World Cup podium two more times in the 2016/17 season , third in Madonna di Campiglio and second in Kranjska Gora.
With eight top 10 placings, Gross was also among the world leaders in the 2017/18 season , with two sixth places in Val-d'Isère and Adelboden being his best results. Due to an increased failure rate, he was only just two times in the top ten in the 2018/19 season .