Click here for full BSB FP1 results at Assen
Josh Brookes has set the early pace at Assen by going quickest in FP1 ahead of surprise package Christian Iddon, while Shane Byrne completes the top three.
The MCE British Superbike championship leader recovered from an early scare during the opening stages to end the session top with a 1m 38.153s, two-tenths ahead of 2014 pole-sitter Iddon on the Bennetts Suzuki, who pinched second from PBM Kawasaki's Byrne as the chequered flag fell.
Jack Kennedy also acted as an unfamiliar face at the sharp end and briefly topped the session before eventually finishing fourth, with Luke Mossey rounding out the top five in his Quattro Plant Kawasaki.
Showdown contender Michael Laverty also enjoyed a positive start in Assen by grabbing sixth with Richard Cooper splitting two Showdown riders in seventh ahead of James Ellison in eighth.
Australian duo Josh Waters and Billy McConnell completed the top ten in the Netherlands, edging out Showdown star Tommy Bridewell in 11th but the final top six rider Honda Racing's Dan Linfoot had a slower start down in 16th.
FP1 was prematurely red-flagged before it really got going after John Hopkin's Lloyds British Moto Rapido Ducati expired on its opening lap, dropping fluid at turn nine which required clearing up. Hopkin's technical problem appeared terminal as he was forced to sit out the entire session and not set a time.
After a 20-minute delay the session resumed with Byrne heading the early proceedings but his joy was short-lived when surprise package Iddon, who grabbed pole position at Assen in mixed conditions last year, put his Bennetts Suzuki top with a 1m 39.060s.
Brookes, who was forced to sit out the first half of the morning session after a small off, quickly demonstrated his impressive pace at the Dutch TT circuit by being the first rider to duck under the 1m 38s barrier.
The Milwaukee Yamaha rider could call upon his experience racing the new YZF-R1 at Assen after he stood in for German squad Team Yamaha MGM in the IDM Superbike championship in August.
Despite a late flurry of improvements the BSB championship leader held on to top spot with Iddon and Byrne in close company.