In December 2013, Pestoni was loaned to Genève-Servette HC for the 2013 Spengler Cup, which he would eventually win. He played a huge role in the title, tallying 4 points (1G/3A) in 4 games. He was again loaned to the reigning champion for the 2014 edition and scored 3 goals to lead Geneva to its second title. He was also named to the tournament All-Star Team.