MANAMA (AFP) - Kimi Raikkonen topped the times and escaped a grid penalty as he and Ferrari team-mate Sebastian Vettel dominated Friday's floodlit second free practice for this weekend's Bahrain Grand Prix.
The Finn clocked a best lap time of one minute and 29.817 seconds around the Bahrain International Circuit to outpace four-time champion Vettel by 0.011 seconds.
The two Ferrari men were comfortably clear by more than half a second of the two Mercedes of Valtteri Bottas and his team-mate, defending champion Lewis Hamilton.
Raikkonen, however, faced a post-race investigation into a possible unsafe release of his car, by Ferrari, following a routine pit-stop late in the session.
He pulled away, but then saw his pit crew waving their arms and pulled up at the side of the track.
It was feared he would be punished for an unsafe release - because his front right wheel was not attached properly - and given a grid penalty, but instead Ferrari were fined 5,000 euros.
The race stewards said they felt Ferrari had done all they could to minimise the risk of the wheel coming off the car.
Bottas was happy to bounce back after his confidence-sapping crash in qualifying in Australia two weeks ago.
He said: "There is always pressure and I am treating this like a normal weekend. Here the track improves all the time, with more grip every lap.
"The car felt ok, but we need to find some more pace especially on a single lap."
Hamilton, who created another minor controversy when he showed his approval, on social media, of the retention of grid girls at the Monaco Grand Prix, said it had been "a normal Friday".
"It's very close and we have some work to do. The tyres feel the best they have here in years, very stable with less degradation."
Dutchman Max Verstappen, who missed the first session due to a power failure, was fifth for Red Bull ahead of team-mate Daniel Ricciardo.
Verstappen said: "We had a small issue this morning - these things happen so it doesn't concern me too much.
"I lost a lot of track time, but come race day it will depend a lot on strategy."
German Nico Hulkenberg was seventh for Renault ahead of the Toro Rosso of Pierre Gasly and the two McLarens of two-time champion Fernando Alonso and Stoffel Vandoorne.