Double British Touring Car Championship champion and Vauxhall driver Jason Plato topped the free practice times as the series makes its second visit of the season to Thruxton.
The Power Maxed Racing driver was the first runner to drop below the 1m17s barrier, and then in the final 10 minutes of second practice he posted an unmatched time of 1m16.414s to the head the order.
Points' leader Colin Turkington set the early benchmark in the final practice session, with the rear-wheel-drive BMW 330i M Sport not requiring a visit to the pits in order to swap the warm front tyres with cold rears, unlike his front-driven competition.
Matt Neal's first representative lap left him some 0.585s adrift in second place, before he was then relegated by the similar FK8 Honda Civic Type R of BTC Racing's Josh Cook.
With 12 minutes to go Plato posted the fastest final sector of the session but, despite the good run across the line, dropped 0.3s in the first half of his next flying lap and so failed to improve.
Then at his next attempt the Vauxhall Astra driver set a 1m16.414s time, strong enough to end the session fastest.
WSR BMW driver Tom Oliphant was a late improver up to second, but was 0.135s shy of Plato in a session that was 0.8s slower than Dan Cammish's practice time of 1m15.589s earlier in the season.
Adam Morgan showed a strong flash of pace to improve his Mercedes A-Class up to third ahead of Tom Chilton - the Ford Focus RS driver taking the risk to scrub a set a new tyres on the abrasive track surface ahead of qualifying.
After early setbacks due to an electrical issue, Andrew Jordan climbed to fifth in his BMW, ahead of Sam Tordoff.
The AmD Tuning driver set a new qualifying lap record with his pole effort earlier in the year, but had his running truncated this time around when the FK2 Civic's front-right wishbone sheered at the high-speed left-hander of Noble.
Tom Ingram was seventh in the revised Toyota Corolla ahead of Turkington and Jack Goff, with the Team Hard Volkswagen CC's having been developed to provide more rear stiffness.
Ollie Jackson rounded out the top 10 ahead of Cook, third-in-the-points Rory Butcher and Matt Neal.
Cammish, fastest in practice acorss the previous four meetings, was only 10th ahead of 2017 champion Ashley Sutton, who was black flagged for a track limits violation with five minutes remaining, but was allowed back out again.
|1||Dan Cammish||Team Dynamics||Honda||1m16.888s||12|
|2||Ash Sutton||BMR Racing||Subaru||0.174s||9|
|3||Josh Cook||BTC Racing||Honda||0.195s||13|
|5||Adam Morgan||Ciceley Motorsport||Mercedes||0.379s||16|
|6||Matt Neal||Team Dynamics||Honda||0.452s||13|
|7||Tom Ingram||Speedworks Motorsport||Toyota||0.483s||16|
|9||Daniel Rowbottom||Ciceley Motorsport||Mercedes||0.584s||22|
|11||Senna Proctor||BMR Racing||Subaru||0.687s||18|
|12||Stephen Jelley||Team Parker Racing||BMW||0.696s||20|
|13||Jason Plato||Power Maxed Racing||Vauxhall||0.707s||14|
|14||Rob Collard||Power Maxed Racing||Vauxhall||0.747s||15|
|15||Jake Hill||Trade Price Cars Racing||Audi||0.930s||18|
|16||Bobby Thompson||Team Hard||Volkswagen||0.939s||13|
|17||Jack Goff||Team Hard||Volkswagen||1.040s||20|
|18||Chris Smiley||BTC Racing||Honda||1.060s||9|
|19||Matt Simpson||Simpson Racing||Honda||1.166s||20|
|20||Sam Tordoff||AmD Tuning||Honda||1.212s||11|
|21||Tom Chilton||Motorbase Performance||Ford||1.267s||17|
|22||Ollie Jackson||Motorbase Performance||Ford||1.290s||13|
|23||Rory Butcher||AmD Tuning||Honda||1.381s||20|
|24||Nicolas Hamilton||Motorbase Performance||Ford||1.847s||21|
|25||Aiden Moffat||Laser Tools Racing||Infiniti||2.000s||18|
|26||Carl Boardley||Team Hard||Volkswagen||2.021s||15|
|27||Rob Smith||Excelr8 Motorsport||MG||2.237s||20|
|28||Mark Blundell||Trade Price Cars Racing||Audi||2.625s||19|
|29||Michael Crees||Team Hard||Volkswagen||3.252s||17|
|30||Sam Osborne||Excelr8 Motorsport||MG||3.946s||18|
|1||Jason Plato||Power Maxed Racing||Vauxhall||1m16.414s||15|
|3||Adam Morgan||Ciceley Motorsport||Mercedes||0.241s||15|
|4||Tom Chilton||Motorbase Performance||Ford||0.319s||15|
|6||Sam Tordoff||AmD Tuning||Honda||0.449s||19|
|7||Tom Ingram||Speedworks Motorsport||Toyota||0.466s||16|
|9||Jack Goff||Team Hard||Volkswagen||0.559s||14|
|10||Ollie Jackson||Motorbase Performance||Ford||0.667s||19|
|11||Josh Cook||BTC Racing||Honda||0.680s||16|
|12||Rory Butcher||AmD Tuning||Honda||0.696s||17|
|13||Matt Neal||Team Dynamics||Honda||0.772s||17|
|14||Jake Hill||Trade Price Cars Racing||Audi||0.871s||18|
|15||Rob Collard||Power Maxed Racing||Vauxhall||0.888s||17|
|16||Bobby Thompson||Team Hard||Volkswagen||0.890s||14|
|17||Chris Smiley||BTC Racing||Honda||0.901s||21|
|18||Senna Proctor||BMR Racing||Subaru||0.930s||20|
|19||Dan Cammish||Team Dynamics||Honda||0.942s||12|
|20||Ash Sutton||BMR Racing||Subaru||0.982s||16|
|21||Daniel Rowbottom||Ciceley Motorsport||Mercedes||0.982s||19|
|22||Stephen Jelley||Team Parker Racing||BMW||1.214s||19|
|23||Matt Simpson||Simpson Racing||Honda||1.380s||15|
|24||Aiden Moffat||Laser Tools Racing||Infiniti||1.589s||17|
|25||Carl Boardley||Team Hard||Volkswagen||1.818s||15|
|26||Michael Crees||Team Hard||Volkswagen||1.933s||16|
|27||Mark Blundell||Trade Price Cars Racing||Audi||2.153s||18|
|28||Rob Smith||Excelr8 Motorsport||MG||2.248s||20|
|29||Nicolas Hamilton||Motorbase Performance||Ford||2.350s||19|
|30||Sam Osborne||Excelr8 Motorsport||MG||2.548s||21|