Reigning champion Colin Turkington headed standings leader Ash Sutton after a late improvement to set the benchmark time in the opening British Touring Car Championship session at Croft.
Following a red flag interruption in the opening quarter of the 40-minute session due to an off for the returning Mike Bushell in the Team HARD-run Volkswagen CC, the remainder of the session would then run cleanly until the chequered flag, with Turkington putting in his best time to go quickest with five minutes remaining.
The Northern Irishman’s time put him over a tenth quicker than current championship leader Ash Sutton in the Laser Tools Racing Infiniti Q50, while Dan Cammish was only 0.033s further behind in the Team Dynamics-run FK8 Honda Civic Type R.
Turkington’s team-mate Tom Oliphant highlighted the strength of the BMW 330i M Sport around the 2.1-mile circuit in fourth position, while MB Motorsport’s Jake Hill – who had led the way at the midway mark in the session before a flurry of late improvements – would ultimately end up completing the top five.
Hill headed fellow Honda runner Josh Cook in the BTC Racing entry, while Oulton Park race three winner Adam Morgan continued his strong Saturday form in the Ciceley Motorsport Mercedes-Benz A-Class.
Triple champion Matt Neal managed eighth fastest in the second of the Halfords Yuasa Racing Hondas, while Sutton’s team-mate Aiden Moffat managed ninth.
Motorbase Performance’s Rory Butcher rounded out the top ten runners on what was effectively a shakedown for his Ford Focus ST following a huge shunt in the final race at Silverstone last time out.
Team HARD’s Jack Goff managed 11th in the fastest of the Volkswagen CCs, while Tom Chilton and Chris Smiley finished the session in 12th and 13th respectively.
Bobby Thompson’s Audi S3 was 14th, while Smiley’s team-mate Senna Proctor completed the top 15 runners in the second Excelr8 Motorsport Hyundai.
Notably, Tom Ingram was hampered by a manifold issue on his Toyota Corolla, limiting his running to only five laps across the session and leaving him last in 26th position.
The second British Touring Car Championship practice session is scheduled to get underway at 12:05 BST.
Session results
| POS | NO | DRIVER | NAT | ENTRANT | CAR | LAPS | TIME | GAP |
| 1 | 1 | Colin TURKINGTON |  |
Team BMW | BMW 330i M Sport | 20 | 1:22.145 | 0.000 |
| 2 | 116 | Ashley SUTTON | |
Laser Tools Racing | Infiniti Q50 | 18 | 1:22.270 | 0.125 |
| 3 | 27 | Dan CAMMISH | |
Halfords Yuasa Racing | Honda Civic Type-R | 15 | 1:22.303 | 0.158 |
| 4 | 15 | Tom OLIPHANT | |
Team BMW | BMW 330i M Sport | 17 | 1:22.309 | 0.164 |
| 5 | 24 | Jake HILL | |
MB Motorsport accelerated by Blue Square | Honda Civic Type-R | 15 | 1:22.385 | 0.240 |
| 6 | 66 | Josh COOK | |
BTC Racing | Honda Civic Type-R | 18 | 1:22.650 | 0.505 |
| 7 | 32 | Adam MORGAN | |
Carlube Triple R Racing with Mac Tools | Mercedes-Benz A-Class | 18 | 1:22.694 | 0.549 |
| 8 | 25 | Matt NEAL | |
Halfords Yuasa Racing | Honda Civic Type-R | 17 | 1:22.731 | 0.586 |
| 9 | 16 | Aiden MOFFAT | |
Laser Tools Racing | Infiniti Q50 | 18 | 1:22.857 | 0.712 |
| 10 | 6 | Rory BUTCHER | |
Motorbase Performance | Ford Focus ST | 13 | 1:22.896 | 0.751 |
| 11 | 31 | Jack GOFF | |
RCIB Insurance Racing with Fox Transport | Volkswagen CC | 16 | 1:22.972 | 0.827 |
| 12 | 3 | Tom CHILTON | |
BTC Racing | Honda Civic Type-R | 14 | 1:22.981 | 0.836 |
| 13 | 22 | Chris SMILEY | |
Excelr8 Motorsport | Hyundai i30 Fastback N | 19 | 1:23.043 | 0.898 |
| 14 | 19 | Bobby THOMPSON | |
GKR TradePriceCars.com | Audi S3 | 13 | 1:23.113 | 0.968 |
| 15 | 18 | Senna PROCTOR | |
Excelr8 Motorsport | Hyundai i30 Fastback N | 14 | 1:23.177 | 1.032 |
| 16 | 48 | Ollie JACKSON | |
Motorbase Performance | Ford Focus ST | 15 | 1:23.300 | 1.155 |
| 17 | 777 | Michael CREES | |
The Clever Baggers with BTC Racing | Honda Civic Type-R | 12 | 1:23.328 | 1.183 |
| 18 | 12 | Stephen JELLEY | |
Team Parker Racing | BMW 125i M Sport | 17 | 1:23.477 | 1.332 |
| 19 | 21 | Mike BUSHELL | |
RCIB Insurance Racing with Fox Transport | Volkswagen CC | 10 | 1:23.602 | 1.457 |
| 20 | 41 | Carl BOARDLEY | |
Team HARD. | BMW 125i M Sport | 18 | 1:23.608 | 1.463 |
| 21 | 44 | Andy NEATE | |
Motorbase Performance | Ford Focus ST | 17 | 1:24.116 | 1.971 |
| 22 | 4 | Sam OSBORNE | |
MB Motorsport accelerated by Blue Square | Honda Civic Type-R | 15 | 1:24.180 | 2.035 |
| 23 | 29 | Jac CONSTABLE | |
Power Maxed Car Care Racing | Vauxhall Astra | 16 | 1:24.387 | 2.242 |
| 24 | 28 | Nicolas HAMILTON | |
ROKiT Racing with Team HARD. | Volkswagen CC | 15 | 1:24.630 | 2.485 |
| 25 | 32 | Jack BUTEL | |
Carlube Triple R Racing with Mac Tools | Mercedes-Benz A-Class | 17 | 1:25.783 | 3.638 |
| 26 | 80 | Tom INGRAM | |
Toyota Gazoo Racing UK with Ginsters | Toyota Corolla | 5 | No time | N/A |