This is the counter to the previous play. The master carries his lance low so as to strike the horse in the head or chest. The player cannot beat such a low attack aside with his sword.
The 5th master rides against you with their sword held in posta di donna, aiming to beat your spear aside and then strike you.
Counter this by ignoring your opponent and attacking their horse instead. Due to the length of the spear and your targeting, you will hit your opponents horse long before your opponent comes within reach.
The surest target is the centre of the horse at the base of its neck. If you hit here, you will drive your lance into its chest with the full momentum of both horses combined. This will kill the horse and pull the lance from your hand. It may seriously disrupt your own balance.
At the other end of the scale of potential targets is the horses face. If you strike there, you will keep a hold of your lance, but remember you are aiming at a moving target. The horse will try to avoid the lance. It doesnt want to be stabbed in the face any more than you do.
At the very least, your opponents horse will uncontrollably bolt, pigrooting and bucking in pain. If you strike it cleanly, it will collapse to the ground and thrash madly as it dies, doing unpredicatable damage to the rider as it does so. Take advantage of the confusion to ride down your opponent before they can recover.