Lewis Hamilton edged Sebastian Vettel in the first practice at the Bahrain Grand Prix on Friday.
Ferrari, meanwhile, continued to struggle with Fernando Alonso finishing 13th and Felipe Massa 15th.
Most drivers quickly adjusted to the dry and dusty circuit, which is holding an F1 race for the first time in two years. The 2011 race was cancelled due to anti-government protests that that have left nearly 50 dead.
Several drivers, though, went off the track at the tricky turn 10. Timo Glock of Marussia spun out on the first corner but the German quickly recovered. He placed 21st of the 23 cars.
Security was tight ahead of the first practice following days of sometimes violent anti-government protests.
There were checkpoints on the roads leading to the track, including at least one where vehicles were scanned with metal detectors.
Additional security troops have been deployed around the circuit and across the capital, Manama. There were no signs of protests at the circuit early Friday.
Supporters of the Shiite opposition plan to rally later Friday against the F1 race. It is backed by the ruling Sunni dynasty but is opposed by demonstrators who contend it rewards a regime that continues to detain political prisoners and commit rights abuses.
On Thursday, there were sporadic clashes, including riot police firing tear gas and stun grenades at protesters chanting anti-F1 slogans. Downtown shops also shuttered early amid the tightened security.
Concerns also grew over the safety of fans and race teams after two members of F1 team Force India decided to leave Bahrain on Thursday. Their decision came a day after a team vehicle was caught in a traffic jam because of a hurled firebomb.
