The Secret Triwizard Challenge

You're not stupid enough to fight a giant spider by choice. You get your wits about you and run as fast as you can towards the other end of the clearing, where an exit lies.
However, the spider lunges at you before you can reach the exit. Its pinchers connect with the back of your shield charm, which protects you from getting seriously hurt, but the blow shoves you to the ground. Your shield charm shatters.
Now, you're on the ground with no protection. The spider was dazed when it hit your shield, but it's quickly coming to. There's not enough time to run, so you'll need to fight. What's your plan of attack?

You have 2 choices: