Mikel Azcona topped the first free practice session at Autodrom Most, narrowly ahead of wildcard Petr Fulin in a good showing for CUPRA.
The FIA World Touring Car Cup was treated to bright, dry conditions for its first on-track session in seven weeks, and it was Jean-Karl Vernay who was the fastest driver out of the blocks. However, there was still plenty of lap time to find at this stage.
Twenty minutes into the session, four seconds had been found by the field, and it was none other than local wildcard Fulin who led the way.
However, fellow CUPRA driver Azcona then became the first driver to break the 1 minute 40 seconds barrier with a lap time of 01:39.654. Nathanael Berthon also found some speed to jump into second place for Audi.
Technical dramas then struck Frederic Vervisch who returned to the pits, while Yann Ehrlacher went third fastest, despite his splitter taking a big hit from the track surface. This weekend, Cyan Racing are running a different, less flexible splitter set-up, as their previous arrangement had been deemed illegal.
Honda find themselves in the same boat, which may well offer a marginal advantage at these early stages to the other manufacturers, who are already familiar with their splitter set-up.
Fulin then pulled another fast lap time out of the bag to overtake Berthon in the standings, just seven hundredths of a second slower than the benchmark set by Azcona.
Esteban Guerrieri, meanwhile, was complaining of poor performance in the braking zones and corner entry from his Honda – no doubt a side effect of its high ballast weight allocation in addition to any other set-up issues needing to be ironed out.
When the chequered flag was waved on this session, it was Santiago Urrutia who emerged in third behind the leading pair of CUPRA drivers. His team-mate Thed Bjork also made late progress to move up to fifth; the pair of them sandwiching Berthon on the results sheet.
Championship leader Ehrlacher ended up sixth-quickest, ahead of Gilles Magnus in seventh.
Initial pace-setter Vernay wound up in eighth, while the top ten was completed by Honda duo, Nestor Girolami and Guerrieri.
Free Practice Two gets underway later this afternoon at 14:30 local time (13:30 BST).
Session results
| POS | NO | NAT | DRIVER | ENTRANT | CAR | LAPS | TIME | GAP |
| 1 | 96 |  |
Mikel AZCONA | Zengő Motorsport | CUPRA Leon Competición TCR | 22 | 1:39.654 | – |
| 2 | 222 |  |
Petr FULÍN | Petr Fulín | CUPRA Leon Competición TCR | 16 | 1:39.724 | 0.070 |
| 3 | 12 |  |
Santiago URRUTIA | Cyan Performance Lynk & Co | Lynk & Co 03 TCR | 19 | 1:39.856 | 0.202 |
| 4 | 17 |  |
Nathanaël BERTHON | Comtoyou DHL Team Audi Sport | Audi RS3 LMS TCR | 18 | 1:39.881 | 0.227 |
| 5 | 11 |  |
Thed BJÖRK | Cyan Performance Lynk & Co | Lynk & Co 03 TCR | 20 | 1:39.976 | 0.322 |
| 6 | 68 | |
Yann EHRLACHER | Cyan Racing Lynk & Co | Lynk & Co 03 TCR | 17 | 1:40.035 | 0.381 |
| 7 | 16 |  |
Gilles MAGNUS | Comtoyou Team Audi Sport | Audi RS3 LMS TCR | 21 | 1:40.102 | 0.448 |
| 8 | 69 | |
Jean-Karl VERNAY | Engstler Hyundai N Liqui Moly Racing Team | Hyundai Elantra N TCR | 19 | 1:40.152 | 0.498 |
| 9 | 29 |  |
Néstor GIROLAMI | ALL-INKL.COM Münnich Motorsport | Honda Civic Type-R FK8 TCR | 17 | 1:40.271 | 0.617 |
| 10 | 86 | |
Esteban GUERRIERI | ALL-INKL.COM Münnich Motorsport | Honda Civic Type-R FK8 TCR | 19 | 1:40.297 | 0.643 |
| 11 | 32 |  |
Tom CORONEL | Comtoyou DHL Team Audi Sport | Audi RS3 LMS TCR | 19 | 1:40.334 | 0.680 |
| 12 | 5 |  |
Norbert MICHELISZ | BRC Hyundai N LUKOIL Squadra Corse | Hyundai Elantra N TCR | 18 | 1:40.397 | 0.743 |
| 13 | 100 | |
Yvan MULLER | Cyan Racing Lynk & Co | Lynk & Co 03 TCR | 18 | 1:40.420 | 0.766 |
| 14 | 79 |  |
Rob HUFF | Zengő Motorsport | CUPRA Leon Competición TCR | 23 | 1:40.437 | 0.783 |
| 15 | 9 | |
Attila TASSI | ALL-INKL.DE Münnich Motorsport | Honda Civic Type-R FK8 TCR | 18 | 1:40.507 | 0.853 |
| 16 | 22 | |
Frédéric VERVISCH | Comtoyou Team Audi Sport | Audi RS3 LMS TCR | 6 | 1:40.541 | 0.887 |
| 17 | 8 |  |
Luca ENGSTLER | Engstler Hyundai N Liqui Moly Racing Team | Hyundai Elantra N TCR | 22 | 1:40.940 | 1.286 |
| 18 | 55 | |
Bence BOLDIZS | Zengő Motorsport Drivers’ Academy | CUPRA Leon Competición TCR | 20 | 1:40.958 | 1.304 |
| 19 | 18 |  |
Tiago MONTEIRO | ALL-INKL.DE Münnich Motorsport | Honda Civic Type-R FK8 TCR | 18 | 1:40.967 | 1.313 |
| 20 | 3 |  |
Gabriele TARQUINI | BRC Hyundai N LUKOIL Squadra Corse | Hyundai Elantra N TCR | 19 | 1:41.230 | 1.576 |