Saturday's seventh and final stage from Saint-Michel-de-Maurienne to Les Bottières-Les Sybelles was just 93.5 kilometres long but contained four categorised climbs including the Col du Mollard, Col de la Croix de Fer and Lacets de Montvernier - all used in this year's Tour de France - with the finish atop the Montée des Bottières.
Haig finished in second place, 12 seconds behind stage winner Matvei Mamykin from Russia and on the same time as overnight leader Marc Soler, the Spaniard already a neo-pro with the Movistar team, who took the race leadership from Austrian Gregor Mühlberger the day previous.
"Haig came from behind, and Mamykin and him kept a furious pace in the finale, which I almost couldn't keep." - Tour de l'Avenir winner Marc Soler
Soler won the eight-day 'Race of the Future' by a margin of 1'09 from the boy from Bendigo, and 2'50 from Mamykin.
It is the second consecutive year an Australian has finished on the podium at the race, Haig's performance equalling Robert Power's second place behind Miguel Ángel López of Colombia in the 2014 edition, the best result by an Australian at the time. Both Haig and Power are contracted to ride for Orica-GreenEDGE from 2016 onwards, where the former has been riding as a stagiaire since August 1.
"I'm really happy to have been crowned (champion) this week and staying strong after such an effort on Friday. The national team was really good all race, with everyone doing a good job at the front of the bunch or into breakaways - they really were an important part of my success," said Soler.
"I really suffered today on the final climb to Bottières. At the Croix de Fer, I kept calm: (Sebastián) Henao only had a minute and a half left of his original gap, around 2'40, and I knew he would be losing energy. I just had to complete the descent and go for it on the last two climbs.
"Dutchman (Sam) Oomen attacked on the flat before the Lacets de Montvernier; four or five riders made moves afterwards and I had to jump after them on the climb to secure my lead. Haig came from behind, and Mamykin and him kept a furious pace in the finale, which I almost couldn't keep. I only had to follow their wheels, but it was tremendous," said the 21-year-old from Barcelona.
"Now it's time to enjoy the victory and complete the season. As the Worlds rules are different than in the Nations Cup, I won't be racing the U23 championships, so I'm waiting for Eusebio to decide which races I'll be enjoying at the end of this debut year."