Does horde breaker work with green-flame blade?

if there are two goblins in front of me and I cast green flame blade on my great sword and hit one with it, can I then use the horde breaker feature from the hunter subclass to hit the second one that I damaged with green-flame. 

GREEN-FLAME BLADE

Evocation cantrip

Casting Time: 1 action

Range: Self (5-foot radius)

Components: S, M (a melee weapon worth at least 1 sp)

Duration: Instantaneous

You brandish the weapon used in the spell's casting and make a melee attack with it against one creature within 5 feet of you. On a hit, the target suffers the weapon attack's normal effects, and you can cause green fire to leap from the target to a different creature of your choice that you can see within 5 feet of it. The second creature takes fire damage equal to your spellcasting ability modifier.

This spell's damage increases when you reach certain levels. At 5th level, the melee attack deals an extra 1d8 fire damage to the target on a hit, and the fire damage to the second creature increases to 1d8 + your spellcasting ability modifier. Both damage rolls increase by 1d8 at 11th level (2d8 and 2d8) and 17th level (3d8 and 3d8).

I only damage the second creature with greenflame but does that disqualify me from horde breaker?

Horde Breaker. Once on each of your turns when you make an attack with a weapon, you can make another attack with the same weapon against a different creature that is within 5 feet of the original target, that is within the weapon's range, and that you haven't attacked this turn.

Sure, though the second attack is just a normal attack with that weapon; you don't get to cast Green-Flame Blade again.

Are you asking, specifically, about the requirement that Horde Breaker be directed at a creature you haven't attacked yet that turn, and whether the second target from Green-Flame Blade is eligible? If so, then the answer is yes; you have dealt damage to that creature, but you haven't attacked it.

Awesome, thanks!