Sebastian Vettel survived a scare on Friday as he and Ferrari proved they are back as serious contenders for this year's world championship by topping both opening practice sessions ahead of this weekend's Bahrain Grand Prix.
The four-time world champion was the quickest man of the day but admitted he had been lucky to recover from a technical problem in the evening's floodlit session when his Ferrari lost power and 'shut down'.
"We had some sort of glitch," he said. "All of a sudden everything went dark. It was a total shutdown.
"Thankfully, there was no lasting damage to the car and we can fix it.
"Nowadays, these cars are not just cars -- it's all technology and software so it seems to me like something went wrong there."
Vettel wound up narrowly ahead of Valtteri Bottas of Mercedes and third-placed Daniel Ricciardo of Red Bull at the end of second practice, the trio separated by 0.06 seconds.
"I think Mercedes looked stronger earlier today, but we were lucky to recover after our issue so overall I think we did ok," he added. "I think we can do better."
Vettel shares the leadership of this year's world championship with three-time champion Lewis Hamilton of Mercedes after two races. Both have 43 points after one win apiece.
Hamilton was unable to clock a flying lap on his set of super-soft tyres in the second session, when he was baulked by Nico Hulkenberg of Renault, and he ended up fifth quickest behind Kimi Raikkonen in the second Ferrari.
Both Hamilton and Hulkenberg were summoned to see the stewards after the session.
"These drivers are just so dangerous, man," said Hamilton on team radio when he took evasive action.
Howver, the Renault driver escaped punishment.
"I just misjudged a bit how fast and how big the speed difference was and ended up in the wrong timing and the wrong spot. It just happens, what can I say? I can't disappear, and I won't," he explained.
While Hamilton revealed his frustration, his new Mercedes team-mate Bottas was inadvertently involved in another incident when the 't-wing' on his Mercedes car detached and flew off.
- 49 degrees -
Max Verstappen in a Red Bull ran over the wing and suffered extensive damage to the floor of his car, which reduced his running to only 18 laps in the floodlit session.
Red Bull team boss Christian Horner called for the wings, small items that are fitted behind the drivers' cockpit on the engine cover, to be banned from the sport.
It was the second time this season that a 't-wing' had fallen off Bottas's car. It also happened in China last weekend.
Ricciardo said he was pleased with his showing after a frustrating non-finish in his home Australian event and missing out on a podium in China where he was beaten to third by 19-year-old Verstappen.
"If that was qualifying, I would take that," said Ricciardo. "It was pretty close to the best lap so it was a good day."
Hamilton added that it was "a pretty normal Friday, really."
He added that it had been "incredibly hot" when the temperature touched 49 degrees Celsius, but the later cooler conditions in second practice had helped him understand his car's performance.
"It was very close today, with Ferrari fastest," he said. "In race trim, they seem a couple of tenths quicker, so I'm expecting a great battle tomorrow and again on Sunday."
Mercedes technical director James Allison said the outcome of the race, and the weekend's work, could be decided by a slight error.
"We can see that it is going to be another really tight weekend between ourselves and Ferrari," he said. "A weekend where the smallest of mistakes could make the difference."