If your faces with a knife try to move a bit to the side then a wrist lock. That's how we do practices. No guarantee you won't get and you have to see it. If it's from behind....not great.
Remember talking to a 1% we maybe 8 or 9 years back in Golburn pub and he carried a small lighter kinda like a mini flame thrower you can buy in a $2 shop....mods delete if inappropriate.
Flashlight is great. I trained many different martial arts and every instructor/sensei said the same thing. If you get in a fight with a knife, it doesn't matter how well trained you are. You will get cut. If the knife is yours, it's still the same. You will get cut. Run and avoid.
Well, most said that. My Ninjutsu instructor said, "dodge the knife, grab his arm, flip him over, bite his balls". I said, "what if he has a sword?", my instructor said, "that's easier. Step to the side, grab his dominant hand, hit his other hand off the hilt, use his sword to cut him through the balls". Dude was obsessed with balls.
Flashlight is great though. High powered flashlight. The kind that aren't sold legally in Australia. Shine that in a bloke's eyes at night and it's basically like a flashbang going off. Blind for enough time to get away safely.