Suzuka, Japan: Championship leader Lewis Hamilton stayed ahead of Mercedes teammate and rival Nico Rosberg in Friday's practice for the Formula One Japanese Grand Prix but both saw their efforts overshadowed by a teenager.
Max Verstappen became the youngest Formula One driver ever, taking part in free practice at Suzuka at the age of 17-years and three days.
Hamilton clocked a best lap time of 1min 35.078sec to finish 0.240 sec ahead of Rosberg, who trails him by three points in the championship standings with five races remaining.
Rosberg, who despite suffering a lock-up on a hairpin, was 0.151sec faster than Hamilton in the opening session and the day's times pointed to another furious Mercedes duel on the high-speed Suzuka layout on Sunday.
"It's been a good day for the team," Hamilton told reporters as the feuding team-mates kept up the appearance of harmony in Japan. "It is a tough track for the tyres and we have a lot of work to do.
"I was nearly off in the barriers once myself," added the 2008 champion from Britain, referring to a heart-stopping slide where he almost lost control of his car.
Hamilton has wiped out a 29-point deficit thanks to victories in the last two races and Rosberg's retirement in Singapore two weeks ago.
Verstappen, son of former Formula One race Jos Verstappen, grabbed the spotlight with his drive for Toro Rosso.
The teenager, who is not old enough to drive on public roads in his native Netherlands, pulled over after 21 laps with smoke billowing from his car.
"I have a problem in the engine," the Dutchman, who will replace Jean-Eric Vergne next season, radioed to his team. "I have smoke out of the engine. What should I do?"
It was a rude introduction to Formula One for the youngster whose entry in the sport has sparked much debate.
"I was not even close to the limit," said Verstappen, who did not run in the second session. "I was just driving safely without doing any crazy stuff."
Finland's Valtteri Bottas was third quickest for Williams
in the afternoon, 1.2 seconds behind the Mercedes pair, but ahead of Briton Jenson Button for McLaren and four-time defending world champion Sebastian Vettel in Red Bull.
Fellow Finn Kimi Raikkonen, the 2007 Formula One champion, was sixth quickest for Ferrari, followed by team-mate and twice champion Fernando Alonso of Spain, who is being strongly linked with a return to McLaren.
Outgoing Ferrari president Luca di Montezemolo told reporters at the Paris Motor Show that Alonso's future was being discussed.
"Alonso is in Japan discussing his future at Ferrari," said Di Montezemolo. "If he will stay, yes, we will be pleased. If we share with him the decision for him to leave then it would be done in the best way for both parties."
The second practice session at Suzuka ended early when Frenchman Vergne's Toro Rosso also ground to a halt with smoke pouring from the rear, resulting in a red flag.
Japan's Kamui Kobayashi also crashed his Caterham and Mexican Esteban Gutierrez lost control of his Sauber while Raikkonen and Nico Hulkenberg both had minor run-offs as rain fell sporadically.