Kimi Raikkonen topped the leaderboard ahead of Ferrari teammate Sebastian Vettel in the second practice session for the Bahrain Grand Prix after Australia’s Daniel Ricciardo had given Red Bull an early boost by clocking the fastest time in the opening session.

Raikkonen and Vettel were up front as cooler temperatures and nightfall on Friday matched the conditions for Sunday evening’s race.

Raikkonen’s time of one minute, 29.8 seconds on the 5.4km desert circuit was a fraction quicker than Vettel’s.

Defending world champion Lewis Hamilton, who had a patchy fifth-placed first practice session, again looked short of speed as he finished fourth in the second outing, just behind Mercedes teammate Valtteri Bottas.

In a boost for Ferrari, both Mercedes cars were more than half a second slower than the best lap set by Raikkonen, who would be investigated by race stewards for an unsafe car release following a pitstop.

Max Verstappen, who failed to register a time in the first session, was fifth, ahead of Ricciardo.

Earlier in the day, Ricciardo was 0.3 seconds quicker than Bottas and 0.4 seconds faster than Raikkonen.

Vettel was fourth while Hamilton fifth. Briton had a tricky first session, locking his tyres and twice taking his Mercedes too wide on corners.

Verstappen’s car lost power and stopped on the track in the first session. He got out and helped stewards wheel it back to the team garage. The Dutch driver spun early into the season-opening Australian GP two weeks ago, finishing in sixth place.

Verstappen complained about a lack of speed in his Red Bull on Friday.

“Why am I so slow on the straights? It’s unbelievable,” he said on his team radio.

There will be a third and final practice session on Saturday before qualifying, when Hamilton will be trying to earn a record-extending 74th pole position.

Vettel won in Melbourne, profiting from an error by Mercedes to finish ahead of Hamilton, who was leading from pole.