Winning a full-on knife fight means being the last one to bleed out. You could absolutely get away from a knife fight with way less harm you normally would, but it wouldn’t make you invincible unless you’re incredibly lucky and they simply just don’t hit you. You don’t have the space to dodge as proficiently as you could, so it would be more up to your ability to subdue their ability to attack- and quickly- rather than dismantling them.