I wondered how this feat and class ability synergized.

Polearm Master says:

While you are wielding a glaive, halberd, pike, quarterstaff, or spear, other creatures provoke an opportunity attack from you when they enter the reach you have with that weapon.

The Fighter Cavalier's Hold the Line says:

Creatures provoke an opportunity attack from you when they move 5 feet or more while within your reach, and if you hit a creature with an opportunity attack, the target’s speed is reduced to 0 until the end of the current turn.

Does this mean if I hit a creature with the opportunity attack from Polearm Master when they first enter my reach, that also reduces their speed to 0 because of Hold the Line?

I wondered how this feat and class ability synergized.

Polearm Master says:

While you are wielding a glaive, halberd, pike, quarterstaff, or spear, other creatures provoke an opportunity attack from you when they enter the reach you have with that weapon.

The Fighter Cavalier's Hold the Line says:

Creatures provoke an opportunity attack from you when they move 5 feet or more while within your reach, and if you hit a creature with an opportunity attack, the target’s speed is reduced to 0 until the end of the current turn.

Does this mean if I hit a creature with the opportunity attack from Polearm Master when they first enter my reach, that also reduces their speed to 0 because of Hold the Line?