Return of Mach's knees

While everyone is having a field day with thinking their belief that Aoki is overated has been validated as the the #1 LW even though he just lost at WW and is still IMO one of the most underated fighters on the UG, anyone else notice that not only is this a huge comeback win for Sakurai, its also the first time he's let his knees go since I think the Menne fight (where I believe he got a TKO due to cuts from those knees) and then of course, there was his demolition of Trigg in the clinch.

Is this Mach's first knee KO with GNP though?

And how the hell can Mach get submitted by David Baron then KO Aoki on the ground in seconds?