This page of the guide to Resident Evil 3 Remake contains a detailed description of the second battle with Nemesis. This duel with the boss takes place in the Clock Tower Plaza. Nemesis attacks Jill by surprise after climbing a bridge leading to the courtyard adjacent to the clock tower. You must defeat Nemesis Stage 2 - he is now a four-legged beast.
The fight begins shortly after leaving the Sewers and entering the bridge leading towards the Clock Tower. Nemesis jumps out of the water to attack Jill by surprise.
You have to complete a partially playable scene. Just run ahead. On the way, Jill will automatically block Nemesis' path and jump over the holes.
You will advance to a full-fledged fight with Nemesis after reaching the round courtyard. You have full control over the character.
The game doesn't allow you to use an item chest just before the start of this fight, but you can find large amounts of stock in the courtyard. Run around its periphery and check the vehicle wrecks. You will get ammunition for the grenade launcher and some healing items.
During the duel, Nemesis tends to use melee attacks. The boss is primarily making single swings with his upper limbs. His more dangerous attacks are a short charge and a powerful ground slam, which happens when the boss is standing on his back limbs.
Try to run as much as you can and dodge at the right times to avoid getting hit be the boss.
You can use all your weapons to attack Nemesis, but the grenade launcher and shotgun are the most effective. If you want to use the grenade launcher, we recommend using Mine Rounds. The boss can easily activate a landmine. This reduces the risk of missed and wasted rounds.
In the later phase of the fight, Nemesis will be running on the roofs of nearby buildings for some time. Don't attack him then, just use your free time to collect supplies.
You have to be careful, because Nemesis will end with a long jump from the roof of one of the buildings. This is the strongest of all Nemesis' attacks. Quickly leave the spot where Jill was when the boss began the jump, as that is exactly where he will want to land. If you don't do that, you can get seriously injured or even die on the spot.
Continue using a grenade launcher and/or shotgun to attack the boss and replenish supplies every time he returns to the rooftops. You have to keep fighting until you get a cut-scene.