Max Verstappen went fastest in first practice for Formula 1's 2020 Turkish Grand Prix, with a time 10.028 seconds slower than the 2011 pole lap on Istanbul Park's new low-grip surface.
The 90-minute session was disrupted during the early, very slow laps when Ferrari's Charles Leclerc slid wide ahead of the final corner and knocked the pitlane entry bollard off its position.
This exposed the bolts holding the bollard in place and the session was red flagged, with the handful of drivers that had set a time yet to produce a lap under two minutes as they struggled for grip on Pirelli's C1 hard tyres on the new surface, which barely rose above 20 degrees all session.
Max Verstappen called the conditions "like ice", while Lando Norris described it as "worse than ice", with the track also featuring wet patches, some of which remained on the surface throughout the session, after it had been washed ahead of the running getting underway.
After an eight-minute delay for the bollard to be replaced, the session restarted, but by the 30-minute mark only three drivers had set a time.
Carlos Sainz Jr had set the first lap at 2m02.840s, although this was immediately deleted for a track limits violation at Turn 1, despite the McLaren driver sliding slowly off the track and clearly not gaining an advantage.
In any case, Sebastian Vettel's 2m01.145 quickly established the very early P1 benchmark on the hards, before Valtteri Bottas headed out as the first Mercedes driver to appear approaching the 20-minute mark.
He also slid off at Turn 1 on his opening lap, after Mercedes had warned him his tyres were "still 20-degrees below target", which meant his first time - a 1m48.426s - was also deleted.
But Bottas then set a string of laps that stood, bringing the fastest time down to 1m43.009s just before 30 minutes had passed.
Nearly 15 minutes later, as the rest of the pack finally began to post times, Verstappen went quickest with a 1m42.753s - also on the hard tyres, which completed most of the running as the teams have an extra set of this compound for the second time in 2020, after the Portimao event, which also took place on newly installed, low-grip asphalt.
Verstappen brought the fastest time down to a 1m41.741s as he completed a series of tours before Bottas emerged after the mid-session lull to work it down to a 1m39.204s just before an hour had passed.
Verstappen's next run meant he improved to a 1m37.151s, set just before the virtual safety car was deployed after Sainz pulled his McLaren over beyond the Turn 7, uphill right-hand hairpin reporting engine and power steering problems.
That left Verstappen in P1 for a long stint before the two Ferrari drivers demoted him approaching the final 15 minutes of the session, with Vettel ahead of Leclerc on a 1m36.085s before the Monegasque driver improved to a 1m35.507s.
By this stage, several drivers had headed out on the medium tyres but did not trouble the head of the times, and George Russell (P20 in the final order) was the only driver to sample the softs, but the Williams driver set his best time on the hards.
Alex Albon went quickest with just over five minutes to go, with a 1m35.318s on the hards, before Verstappen retook first place with his final effort on that compound in the final two minutes - a 1m35.077s - passing Antonio Giovinazzi off the track using DRS as he flew through the high-speed kink on Turn 11, which separates the track's two main straights.
Albon ended up second fastest in the final order, with Leclerc third and Pierre Gasly, who spun at Turn 1 during the middle phase of the session, the fastest medium-shod runner in fourth on a 1m35.543, 0.430s slower than Verstappen.
Vettel finished fifth ahead of Daniil Kvyat, Lando Norris and Giovinazzi, with this trio also using the mediums to set their fastest times.
Bottas wound up ninth, using the hard rubber throughout the session, with Esteban Ocon rounding out the top 10.
Lewis Hamilton did not head out on to the track until 40-minutes had passed, with the world champion, who can clinch his seventh title this weekend, not setting a time until the final 20 minutes of the session.
He eventually finished 15th in the final order, 5.148s off Verstappen's pace, also on the hard tyres.
Several drivers spun in the second half of the session, with Kvyat and Latifi looping around in the slow final corners by the pitlane entry, while Bottas and Verstappen - on his in-lap after his fastest time had been posted - going around at a faster speed at the 90-degree left Turn 9.
F1 Turkish GP - FP1 results
|1||Max Verstappen||Aston Martin Red Bull Racing||1m35.077s|
|2||Alexander Albon||Aston Martin Red Bull Racing||0.241s|
|3||Charles Leclerc||Scuderia Ferrari||0.430s|
|4||Pierre Gasly||Scuderia AlphaTauri Honda||0.466s|
|5||Sebastian Vettel||Scuderia Ferrari||0.543s|
|6||Daniil Kvyat||Scuderia AlphaTauri Honda||1.661s|
|7||Lando Norris||McLaren F1 Team||2.139s|
|8||Antonio Giovinazzi||Alfa Romeo Racing ORLEN||2.426s|
|9||Valtteri Bottas||Mercedes-AMG Petronas Formula One Team||2.552s|
|10||Esteban Ocon||Renault DP World F1 Team||3.351s|
|11||Nicholas Latifi||Williams Racing||3.431s|
|12||Sergio Perez||BWT Racing Point F1 Team||3.535s|
|13||Lance Stroll||BWT Racing Point F1 Team||4.407s|
|14||Romain Grosjean||Haas F1 Team||4.948s|
|15||Lewis Hamilton||Mercedes-AMG Petronas Formula One Team||5.148s|
|16||Kimi Raikkonen||Alfa Romeo Racing ORLEN||5.958s|
|17||Kevin Magnussen||Haas F1 Team||6.777s|
|18||Daniel Ricciardo||Renault DP World F1 Team||10.079s|
|19||Carlos Sainz Jr.||McLaren F1 Team||11.385s|
|20||George Russell||Williams Racing||14.179s|