Chris Smiley headed up the times in the sole British Touring Car Championship practice session of the weekend at Thruxton, beating team-mate James Dorlin by just under a tenth of a second on a medium-tyre run.
It had been the NAPA Racing UK drivers who had led the times for much of the session, before Smiley hit the top of the times with just over eight minutes to go, lapping in 1 minute 15.434 seconds.
The Hyundai driver then improved even further to end with a 1:15.365 shortly before being black-flagged for exceeding track limits too many times.
In the end, the Northern Irishman had done enough on the faster medium-compound tyre near the end of the session to remain on top, as team-mate Dorlin trailed him by just 0.093 seconds.
NAPA’s Ash Sutton was left to hold third as the top Ford driver, 0.359 seconds adrift, ahead of Power Maxed Racing’s Mikey Doble in fourth, the Audi racer being just over half a second off the best time.
Josh Cook was the top Toyota driver in fifth, ahead of Laser Tools Racing’s Árón Taylor-Smith in sixth, the Irishman improving late in the session.
Dan Cammish had briefly been fastest after ten minutes of the session, but the NAPA driver ultimately finished in seventh, ahead of reigning champion Tom Ingram in eighth, who was the quickest of the Team VERTU-run Hyundais.
The top ten was completed by Plato Racing’s Adam Morgan and Laser Tools Racing’s Gordon Shedden.
Series returnee Senna Proctor was 14th for NAPA Racing, the last driver within a second of the pace, whilst rookie Lewis Gilbert was 21st in his first practice session in the WSR-run BMW, over two seconds off the pace.
The BMW drivers seemed to lack practice pace early on Saturday, with Charles Rainford only 13th and Daryl De Leon in 16th.
Qualifying is scheduled to get underway at 14:00 BST.
Free practice result
| POS | NO | NAT | DRIVER | ENTRANT | CAR | LAPS | TIME | GAP |
| 1 | 22 |  |
Chris SMILEY | Restart Racing | Hyundai i30 Fastback N | 22 | 1:15.365 | – |
| 2 | 132 | |
James DORLIN | Restart Racing | Hyundai i30 Fastback N | 20 | 1:15.458 | 0.093 |
| 3 | 116 | |
Ashley SUTTON | NAPA Racing UK | Ford Focus Titanium | 22 | 1:15.724 | 0.359 |
| 4 | 88 | |
Mikey DOBLE | LKQ Euro Car Parts with Power Maxed Racing | Audi A3 Saloon | 21 | 1:15.877 | 0.512 |
| 5 | 66 | |
Josh COOK | Speedworks Corolla Racing | Toyota Corolla GR Sport | 22 | 1:15.890 | 0.525 |
| 6 | 50 |  |
Árón TAYLOR-SMITH | Laser Tools Racing with MB Motorsport | Toyota Corolla GR Sport | 20 | 1:15.898 | 0.533 |
| 7 | 27 | |
Dan CAMMISH | NAPA Racing UK | Ford Focus Titanium | 21 | 1:15.900 | 0.535 |
| 8 | 80 | |
Tom INGRAM | Team VERTU | Hyundai i30 Fastback N | 16 | 1:15.912 | 0.547 |
| 9 | 33 | |
Adam MORGAN | Cataclean Plato Racing | Mercedes A35 Saloon | 20 | 1:16.071 | 0.706 |
| 10 | 52 | |
Gordon SHEDDEN | Laser Tools Racing with MB Motorsport | Toyota Corolla GR Sport | 19 | 1:16.120 | 0.755 |
| 11 | 32 | |
Daniel ROWBOTTOM | Cataclean Plato Racing | Mercedes A35 Saloon | 21 | 1:16.148 | 0.783 |
| 12 | 11 | |
Ricky COLLARD | Team VERTU | Hyundai i30 Fastback N | 22 | 1:16.173 | 0.808 |
| 13 | 99 | |
Charles RAINFORD | WSR | BMW 330i M Sport | 24 | 1:16.293 | 0.928 |
| 14 | 18 | |
Senna PROCTOR | NAPA Racing UK | Ford Focus Titanium | 23 | 1:16.357 | 0.992 |
| 15 | 3 | |
Tom CHILTON | Team VERTU | Hyundai i30 Fastback N | 20 | 1:16.447 | 1.082 |
| 16 | 2 |  |
Daryl DE LEON | WSR | BMW 330i M Sport | 20 | 1:16.511 | 1.146 |
| 17 | 7 | |
Ryan BENSLEY | Speedworks Corolla Racing | Toyota Corolla GR Sport | 25 | 1:16.619 | 1.254 |
| 18 | 16 | |
Aiden MOFFAT | LKQ Euro Car Parts with Power Maxed Racing | Audi A3 Saloon | 18 | 1:16.826 | 1.461 |
| 19 | 15 | |
Lewis SELBY | NAPA Racing UK | Ford Focus Titanium | 25 | 1:17.028 | 1.663 |
| 20 | 17 | |
Dexter PATTERSON | Steel Seal with Power Maxed Racing | Audi A3 Saloon | 21 | 1:17.291 | 1.926 |
| 21 | 29 | |
Lewis GILBERT | WSR | BMW 330i M Sport | 21 | 1:17.619 | 2.254 |
| 22 | 28 | |
Nicolas HAMILTON | Team VERTU | Hyundai i30 Fastback N | 25 | 1:17.956 | 2.591 |