Sol was clued in by the Padawan's sudden shift in step that they'd noticed the knife's changed course. Vren focused on the knife, and that's where Sol found an opening. He did pretty well in his "Anatomy of Your Opponent" class back at the academy.
As Vren threw himself into a spin to avoid the knife Sol's left fist clenched tightly, wrapping the Force in iron bands around the Padawan's load-bearing pivot knee, intending to lock it in place while Vren focused on dodging and manipulating the knife. Combined with Vren's own twisting body weight thrown into a spin, this would dislocate the knee with a crunchy pop and send him tumbling. With any luck, the sudden burst of pain would also break Vren's focus on the knife.
Vren's hot-potato-esque knife return somewhat surprised Soleil. He quickly shuffled stepped left and turned his vibrosword to present its flat side forward like angled armor in front of his stomach. The knife struck with a ringing clang and careened off, the thin blade snapping free from the hilt. Its hilt clattered across the ground while the blade flew in an awkward arc, the tip swiping across Sol's sword arm to leave a long, shallow cut as it passed before flying into the branches of the tree far behind him.
He barely felt its sting with all the adrenaline and doubted the Jedi felt his little cut either. Soleil kept walking forward, a thin rivulet of blood dripping along his arm.
@Orbit