2015 was a breakthrough year for Alaphilippe.
He acted as a supporter role in the Ardennes classics to help his teammate, the reigning world champion Michał Kwiatkowski, but surprisingly finished 7th in the Amstel Gold Race behind winner Kwiatkowski.
In La Flèche Wallonne, his first time participating in the race, he continued to support Kwiatkowski but found his teammate too far behind at a crucial juncture.
His team director told him to go for the win and he finished second after three-time winner Alejandro Valverde.
The scenario repeated itself at Liège–Bastogne–Liège a few days later when Alaphilippe finished 2nd in his La Doyenne debut, again behind Valverde.
In doing so, Alaphilippe recorded the best French performance at the race since 1998, when Laurent Jalabert finished second.

After those performances and a string of podium finishes in the Tour de Romandie, Alaphilippe was, on 4 May, granted a contract extension for two more years, until the end of 2017.
Later in the month he won the queen stage of the Tour of California and took over the lead in the general classification, 2 seconds ahead of Peter Sagan.
However, he lost the overall eventually to Sagan by just 3 seconds in the last stage due to the time bonuses in a flat sprint.
In the later part of the summer, he finished eighth in the Clásica de San Sebastián, finishing in the lead group behind the winner, Adam Yates.
He subsequently finished tenth overall in the Eneco Tour, which included a stage that used many of the Ardennes classics roads.
His form was dropped significantly near the end of the year, including a DNF in the Road World Championships.
He was later diagnosed with infectious mononucleosis.
The disease led to extreme fatigue, rendering him unable to maintain his top performance and marking the end of his season.
2015 was a breakthrough year for Alaphilippe. He acted as a supporter role in the Ardennes classics to help his teammate, the reigning world champion Michał Kwiatkowski, but surprisingly finished 7th in the Amstel Gold Race behind winner Kwiatkowski. In La Flèche Wallonne, his first time participating in the race, he continued to support Kwiatkowski but found his teammate too far behind at a crucial juncture. His team director told him to go for the win and he finished second after three-time winner Alejandro Valverde. The scenario repeated itself at Liège–Bastogne–Liège a few days later when Alaphilippe finished 2nd in his La Doyenne debut, again behind Valverde. In doing so, Alaphilippe recorded the best French performance at the race since 1998, when Laurent Jalabert finished second.
After those performances and a string of podium finishes in the Tour de Romandie, Alaphilippe was, on 4 May, granted a contract extension for two more years, until the end of 2017. Later in the month he won the queen stage of the Tour of California and took over the lead in the general classification, 2 seconds ahead of Peter Sagan. However, he lost the overall eventually to Sagan by just 3 seconds in the last stage due to the time bonuses in a flat sprint. In the later part of the summer, he finished eighth in the Clásica de San Sebastián, finishing in the lead group behind the winner, Adam Yates. He subsequently finished tenth overall in the Eneco Tour, which included a stage that used many of the Ardennes classics roads. His form was dropped significantly near the end of the year, including a DNF in the Road World Championships. He was later diagnosed with infectious mononucleosis. The disease led to extreme fatigue, rendering him unable to maintain his top performance and marking the end of his season.
Julian Alaphilippe