Thruxton maestro Cook leads Sutton in opening practice
Not for the first time around the Hampshire circuit, the eight-time Thruxton race winner propelled himself to the top of the timesheets by almost 0.5s ahead of championship leader Ash Sutton.
Cook was the only driver to dip under the 1'16 barrier after producing a 1'15.577s lap aboard his One Motorsport Honda Civic Type-R.
Fresh off the back of his first win of the 2023 campaign, defending champion Tom Ingram was third quickest for the EXCELR8 Motorsport Hyundai squad ahead of the Laser Tools Racing BMW of Jake Hill in fourth position.
Although Cook's lap put him almost 0.5s clear of anyone else, little under 0.2s could separate Sutton's time in second down to Rory Butcher and Dan Cammish's best efforts in fifth and sixth.
Power Maxed Racing's Aron Taylor-Smith impressed with the seventh quickest time aboard his Vauxhall Astra, ahead of four-time champion Colin Turkington in eighth.
Team HARD's Dan Lloyd and Team BMW's Stephen Jelley completed the remainder of the top-ten order in ninth and tenth.