Reigning British Touring Car champion Ash Sutton has set the pace during opening practice after an incident packed session at Knockhill.

The Subaru driver left it late in the session to bolt to the top of the timesheets, at the expense of WIX Racing's Jack Goff, as the chequered flag fell after 40-minutes of running.

With the BTCC field tackling the 1.2 mile Knockhill circuit for the first time since being resurfaced, Sutton's best lap [51.293s] has already eclipsed Jason Plato's previous lap record, set in 2016, by over 0.2s.

Having led most the session, Goff settled for second behind the leading Subaru Levorg as the Honda Civic Type-R driver looks to bounce back from a lacklustre Rockingham weekend.

On a circuit which usually tends to favour the RWD runners, Andrew Jordan proved the quickest of the BMW contingent following the weekend's initial running after setting the third fastest time ahead of Rob Austin in fourth.

Austin will be hoping his luck changes after a poor run of form has left the Alfa Romeo Giulietta driver a distant 16th in the drivers' standings.

Team HARD's Mike Bushell has retained his place at the sharp end following a positive weekend at Rockingham after completing the top-five FP1 order in fifth.

Motorbase Performance's Tom Chilton was sixth fastest aboard his Ford Focus RS, ahead of Mercedes A-Class duo Tom Oliphant and Adam Morgan in seventh and eighth.

Sam Tordoff and Tom Ingram completed the remainder of the top-ten order in ninth and tenth.

Elsewhere, championship leader Colin Turkington was 18th fastest, over 0.6s shy from Sutton's front-running pace.