Ferrari enjoyed a productive opening day at the Bahrain Grand Prix as they showed enough pace to keep rivals Mercedes at bay.
Kimi Raikkonen produced the fastest time across Friday's sessions in FP2 as the Ferrari excelled on supersoft tyres – the Finn stopping the clock at one minute, 29.817 seconds.
That saw him finish one hundredth of a second clear of team-mate Sebastian Vettel, who will be looking to build on victory at the opening race of the 2018 season in Melbourne.
While Ferrari's speed impressed under the lights, Mercedes were surprisingly off the pace as Valtteri Bottas and Lewis Hamilton finished over half a second behind Raikkonen.
Hamilton's deficit to the Finn was 0.655secs, a result that compounded a tough day after finishing over a second adrift of Daniel Ricciardo's Red Bull in FP1.
The earlier session offered little insight into what might happen in Sunday's race given it took place in daylight, but Ricciardo proved strong late on to usurp Bottas and Raikkonen.
READ MORE: Bahrain Grand Prix - full race preview
His team-mate Max Verstappen did not fare so well as an electrical fault limited him to installation laps, although he ended FP2 above Ricciardo.
The Red Bulls completed the top six as Formula One's three dominant teams flexed their muscles on the day owner Liberty Media proposed changes that would create a more competitive paddock.
Budget restrictions and simplified power units were among the changes suggested on Friday, alterations that received backing from McLaren, Williams and Haas at the team bosses' media conference.
Such support came as no surprise given their performances on the track, Williams finding it particularly difficult as Lance Stroll and Sergey Sirotkin finished FP2 17th and 18th respectively.
"We know that there are three key areas of weakness that we need to focus on, which we're doing now," Claire Williams told reporters.
"We certainly believe we have more performance to extract from the car and that's what the team are working on at the moment."
McLaren's two drivers occupied ninth and 10th, while Haas had to settle for 11th and 15th as Romain Grosjean outperformed Kevin Magnussen.