De Fabiani took part in junior races of the Alpine Cross-Country Ski Cup until 2013 . He finished second in the U20 overall ranking in the 2012/13 season . In the 2013/14 season he competed in the Alpine Cup. He finished two second places and won the 3.3 km freestyle in Valdidentro . In the overall standings, he took second place. He started in the Tour de Ski 2013/14 , which he did not finish. His best stage result was 50th place in the 15 km mass start race in Lenzerheide . His best placement at the 2014 Winter Olympics in Sochi was 22nd place in the skiathlon . He ran his first World Cup race at the beginning of the 2014/15 season in Ruka , which he finished in 66th place in the sprint. One day later he got his first World Cup points with the 13th place over 15 km. He finished the Tour de Ski 2015 in 24th place overall. He achieved the best time of the day in the 15 km pursuit race in Oberstdorf . At the Nordic World Ski Championships in 2015 in Falun , he finished 40th in the skiathlon, 32nd in the 50 km mass start race and fourth in the relay. In March 2015 he clinched his first classic World Cup victory in Lahti over 15 km. He finished the season in 22nd place in the overall World Cup ranking, 13th place in the distance ranking and first place in the U23 ranking. After fourth place at the Nordic Opening in Ruka at the beginning of the 2015/16 season, he finished ninth at the 2016 Tour de Ski . He finished third in the 15 km mass start race in Oberstdorf. In the further course of the season he came in Nové Město with the relay in third place and in Falun in second place in the 15 km mass start race. At the end of the season he achieved 19th place in the Ski Tour Canada and reached 12th place in the overall World Cup, 11th place in the Distance World Cup and, as in the previous year, first place in the U23 classification. In the following season he finished 17th in the World Cup mini tour in Lillehammer and 14th in the Tour de Ski 2016/17 , reaching 25th place in the overall and distance World Cup. At the Nordic World Ski Championships 2017 in Lahti, he finished 40th over 15 km classic and eighth place in the relay. After finishing 43rd in the Ruka Triple at the beginning of the 2017/18 season, he achieved three top ten finishes in the 2017/18 Tour de Ski , which he ended prematurely, including third place in Oberstdorf in the 15 km mass start race. At the highlight of the season, the 2018 Winter Olympics in Pyeongchang , he finished 22nd in the 50 km mass start race, 20th in the skiathlon and seventh in the relay. At the end of the season he finished third in the 15 km mass start race at the World Cup finals in Falun, which he finished in 12th place, and finally reached 23rd place in the overall World Cup and 17th place in the Distance World Cup.
In the 2018/19 season, De Fabiani finished 12th in the Lillehammer Triple and ninth place in the Tour de Ski 2018/19 . He achieved second place in the 15 km mass start race in Oberstdorf and in the Fiemme Valley . In February 2019 he finished second in the sprint in Cogne . At the Nordic World Ski Championships 2019 in Seefeld in Tirol , he and Federico Pellegrino won the bronze medal in the team sprint. At the end of the season he achieved fourth place at the World Cup finals in Québec and finally reached 11th place in the Sprint World Cup, seventh place in the overall World Cup and sixth place in the Distance World Cup. The following season he achieved 32nd place in the Ruka Triple and 13th place in the ski tour, 30th place in the overall World Cup.
Participation in World Championships and Olympic Winter Games
Olympic games
2014 Sochi : 21st place 30 km skiathlon, 25th place 50 km freestyle mass start, 30th place 15 km classic
2018 Pyeongchang : 7th place relay, 20th place 30 km skiathlon, 22nd place 50 km classic mass start
Nordic World Ski Championships
2015 Falun : 6th place relay, 32nd place 50 km classic mass start, 40th place 30 km skiathlon
2017 Lahti : 8th place relay, 40th place 15 km classic
2019 Seefeld in Tirol : 3rd place team sprint classic, 8th place sprint freestyle, 10th place relay, 14th place 50 km freestyle mass start, 20th place 15 km classic
Italy
Lahti