Any effort on the sabertooth's part to strike at Haruto is considerably hampered by Gary's successful lunging and Iskierka continuing to be very, very talented at being a dragon. It snarls and is slowed by the effort to dislodge the makeshift spear, and that's enough time for Haruto to lunge first. He has no idea where its heart would be but he knows where the throat is, and he slashes for that with all his might, the blade of his knife hitting true and tearing deep.

It's not enough to kill the sabertooth cat immediately, though. It snarls and lashes out with its enormous claws, but Haruto is not inclined towards sticking around to let something get a free hit in on him. He lets his momentum carry him most of the way to safety before turning and preparing to either spring back in at it or dive out of the way of a more purposeful counter attack.

It's bleeding out, though, and doesn't look like it's going to manage a whole lot more other than some angry death throes.