Bahrain FP1: Raikkonen and Vettel on top

Kimi Raikkonen led a Ferrari one-two in first practice for the Bahrain Grand Prix on Friday while Formula One champions Mercedes lurked well down the timesheets after doing their own thing.

Championship leader Lewis Hamilton was only 16th fastest while Mercedes team mate Nico Rosberg was 15th, with Raikkonen and team mate Sebastian Vettel putting in their fastest laps late in the session.

With the action starting amid track temperatures of 53 degrees Celsius, far hotter than will be the case in qualifying and Sunday's twilight race, Mercedes opted for a different approach and longer runs.

"Don't expect any stellar jumps up the order before end of session. Our tyres have 15 laps on them where others will be running fresh sets," the team said on Twitter, before bringing both cars back to the garage nine minutes before the end.

Raikkonen's quickest lap of 1:37.827 seconds came towards the end after temperatures had dropped to the mid-40s.

Finland's Valtteri Bottas was third fastest for Williams with Spanish rookie Carlos Sainz fourth in a Toro Rosso, ahead of Red Bull's Australian Daniel Ricciardo.

McLaren's Spaniard Fernando Alonso was seventh on the timesheets after briefly filling the top spot for a team struggling for performance at the start of their new Honda partnership.

Team mate Jenson Button, however, failed to record a lap time after spinning and stopping on track in the opening minutes with what appeared to be an engine shutdown.

Mercedes are expected to dominate Sunday's race, with world champion Hamilton and Rosberg determined to win another duel in the desert after last year's thriller and a recent spat between the pair in China.

"I think with these tyres and with Ferrari in the mix, I think we could see a real special race here," Hamilton predicted on Thursday.

"Last year I didn't qualify on pole here, I've never been on pole here so that's the challenge but as long as it doesn't get in the way of the challenge of trying to win the race," added last year's winner.

[highlight ]Bahrain Grand Prix, Sakhir - Friday, 17 April 2015[/highlight]