Using the Super-soft tyres, Raikkonen lapped the Sochi Autodrom in 1:36.074s, which was 0.045s quicker than Bottas's best effort, having topped the session early on, and looking the more comfortable Mercedes driver, as Lewis Hamilton struggled to find a balance, and ended up third, nearly half a second down on Bottas.
Max Verstappen and Daniel Ricciardo were split in the order by the other Ferrari of Sebastian Vettel, who failed to set a clean lap on the super-softs, with a mistake at Turn 14 on one lap, and a spin at Turn 17 on the next.
Sergio Perez was best of the rest in seventh, ahead of the Williams pair of Felipe Massa and Lance Stroll, with Esteban Ocon in 10th, in the sister Force India, to make it last season's top five teams filling the top 10 in the timing sheets.
Early change in strategy
Early on i the opening 90 minutes, the teams realised that the Soft tyres would be able to easily complete a full race distance, owing to the low-abrasive nature of the tarmac in Sochi. Therefore, most of the session was run with the Super-soft tyres, as teams need to know whether the best race-strategy is Ultra-soft or Super-softs in the first stint, before the switch to Softs to go to the end.
Sergey Sirotkin took over Nico Hulkenberg's seat at Renault for the first session, although coming out of the pits after just a single install lap, the RS17 ground to halt at Turn 3, and despite his best efforts, the Russian was unable to get going again and sat out the rest of the session.
Hamillton then came through to set a mid 1:39 on soft tyres, although Vettel then quickly bettered that effort with a 1:38.709, on his first lap of the day.
Bottas then went quickest, a 1:36.998, taking him P1, with the super-soft tyres.
Hamilton responded to return to P1, albeit again briefly as Bottas continued to improve, evantually out-pacing his team-mate by 0.562.
Raikkonen, on the super-softs, backed off on the first flying lap, but on his second, improved by 1.67 seconds from soft to super--softs, to pip fellow Finn Bottas by 0.045s.
Ocon loses his engine cover
Earlier, this week, the strategy group banned the shark-fins and T-wings from 2018, although Ocon decided he wanted rid now, by shedding his engine cover on the main straight, with just under 30 minutes to go. The session was briefly red-flagged while the debries was retrieved by marshalls and the Frenchman was able to limp home and get a new one fitted before heading back out.
The lack of grip early on, meant many drivers ran wide, with Hamilton collecting the award for most offs, including one at Turn 2, when he nearly clouted the newly installed kerb and at 14, when he nearly rammed the wall at the end of the back-straight.
Things were going well for McLaren, although its session ended with Stoffel Vandoorne reporting "no power, no power", as he came in at the end of the run, with just four minutes left on the clock.
|4.||Max Verstappen||Red Bull||+1.100s|
|6.||Daniel Ricciardo||Red Bull||+1.216s|
|7.||Sergio Perez||Force India||+1.383s|
|10.||Esteban Ocon||Force India||+1.991s|
|11.||Danill Kvyat||Toro Rosso||+2.422s|
|14.||Carlos Sainz Jr||Toro Rosso||+2.902s|
|20.||Sergey Sirotkin||Renault||NO TIME|