In February and March 2015, Haig led Georgia to their second consecutive Grand Slam in the 2015 ENC. He firstly led the team to a 64–8 win over Germany, before narrowly beating Portugal 20–15 at home. Against Spain he secured a 26–13 win in Madrid, a 33–0 win over Russia, before beating Romania 15–6 to retain the Antim Cup for 5 consecutive years. Unfortunately for Haig and Georgia, the team was unable to retain their form in the 2015 World Rugby Tbilisi Cup, where they lost back to back matches to Emerging Italy 26–10 and Emerging Ireland 45–12. They did however open the tournament with a 19–10 win over Uruguay.