Click here for full BSB FP2 results from Assen.
Josh Brookes has stormed ahead of the chasing pack at Assen by pulling out over 0.7s on his closest rival Luke Mossey as the rest of the Showdown contenders struggle in changeable conditions.
The Milwaukee Yamaha rider has taken a clean sweep of the Friday practice sessions and appears to be in ominous form ahead of the opening races in the MCE British Superbike Showdown after notching up lap record pace, with his quickest lap exactly two-tenths under the existing lap record set by Alex Lowes in 2013.
Quattro Plant Kawasaki's Luke Mossey continued to impress in his rookie year by taking second on the timesheet ahead of second fastest in FP1 Christian Iddon. Brookes' new Milwaukee Yamaha team-mate Jakub Smrz has adapted to the new R1 almost immediately by grabbing fourth while Team WD-40 Kawasaki's Jack Kennedy caught some attention by rounding out the top five.
This displaced defending BSB champion Shane Byrne down to sixth after he briefly headed proceedings in a session which began damp but quickly dried out under bright blue sky in the Netherlands.
Fellow Showdown contenders Michael Laverty and James Ellison followed Byrne in seventh and eighth respectively, as Richard Cooper and Danny Buchan completed the top ten.
The remaining two title fighters suffered difficult FP2 sessions with Dan Linfoot stuck in 17th, while Tommy Bridewell ended the day down in 22nd.
The BSB field has been reduced to 27 riders after James Westmoreland dramatically split from JG Speedfit Kawasaki in between the two sessions at Assen.
After rain dampened the Assen circuit FP2 got off to a slow start with only a handful of riders testing the grip levels while the rest of the paddock eagerly watched on from the pits.
It took until midway through FP2 until lap times of note began to appear on the timesheet and when Brookes became the first rider to duck under the 1m 40s mark the majority of the field took it as their cue to venture out.
With the track effectively dry Byrne laid down a marker with a quick lap, a 1m 38.054s, which forced his main title rival Brookes to respond. The Milwaukee Yamaha rider duly accepted in some style with a 1m 37.4s to pull out over six-tenths of Byrne.
Not satisfied with his work Brookes proceeded to go even quicker to go under the existing BSB lap record at Assen with a 1m 37.072s, nearly a full second faster than Byrne.
As FP2 entered the final couple of minutes Mossey, Iddon, Smrz and Kennedy all displaced the defending BSB champion while the other Showdown contenders remained off the pace.