This video gives a good overview of why you don't want to get into a knife fight. Best option is to gain a distance and escape. A long wooden board or something equivalent could be useful to maintain distance while looking for an opening to run.
https://m.youtube.com/watch?v=-s7E-PsMJRI&pp=ygUaa25pZmUgZmlnaHQgZGVmZW5zZSBtYXJrZXI%3D