In 2010, Cornes took out his third John Cahill Medal and confirmed his reputation as the club's most consistent player through a new attacking role that went beyond his previous role of merely tagging the opposition's best players. His 36-possession, 2-goal game against the Western Bulldogs in Round 16 of that year was a highlight, in addition to a 38-possession effort against West Coast late in the year. Instrumental in the Power's late season fortunes, he was well-deserving of his third best and fairest merit and highlighted his durability as a mainstay of the Port Adelaide engine room.