Lewis Hamilton fears Mercedes could lose second spot to Ferrari in the constructors’ championship after he admitted it will be a scramble to qualify in the top 10 for Sunday’s Abu Dhabi Grand Prix.

Ferrari’s Charles Leclerc topped practice at the Yas Marina Circuit, seeing off McLaren’s Lando Norris by just 0.043 seconds, with world champion Max Verstappen third.

But George Russell and Hamilton finished only sixth and eighth respectively for Mercedes, with the latter half a second behind Leclerc.

Mercedes, who are facing up to their first winless season since 2011, hold only a four-point lead over Ferrari heading into Sunday’s finale in the desert.

And Hamilton said: “It was not the greatest of days. We have had difficult qualifying sessions this year, and getting out of Q1 and into Q2 has always been a tough battle, and getting into Q3 is a challenge.

“The work tomorrow is to try and get into Q3. But it is going to be close.”

Hamilton completed only four timed laps on Friday. He made way for the team’s Danish junior driver Frederik Vesti in the opening running, before a combined 30-minute delay wiped out half of the one-hour second session after Carlos Sainz and Nico Hulkenberg both crashed out.

Russell fared better than Hamilton, but he still finished three tenths behind Leclerc.

However, it was not a day without incident for Ferrari following Sainz’s crash.

A week after a loose drain cover tore through his Ferrari in Las Vegas, Sainz was in the wars again, but on this occasion it was through driver error.

Sainz – who appeared to be put off by another car arriving from the pits – lost control of his machine through turn three and ended up in the barrier.

Carlos Sainz Carlos Sainz crashed out of second practice in Abu Dhabi (Tim Goode/PA)

Although the Spaniard was unharmed in the high-speed smash after just eight and a half minutes, he sustained significant damage to his car, with the sidepods, floor, rear suspension and front wing of his Ferrari all destroyed.

Sainz’s impact also left the barrier in a mess, and a 22-minute delay ensued as the tyre wall was repaired.

But only moments after the running restarted, the red flag was out again – this time after Nico Hulkenberg crashed on the exit of turn one.

On cold tyres, the German was too hasty on the throttle, sliding into the barrier before pulling up in his wounded machine.

The stoppages arrived as a blow to half the grid who sat out the opening session as 10 rookie drivers – including three Britons – were earlier blooded at the Yas Marina Circuit.

British drivers Zak O’Sullivan, 18, and Jake Dennis, 28, made their Formula One weekend debuts for Williams and Red Bull respectively, while Ollie Bearman, 18, who in Mexico became the youngest debutant from Britain at a Grand Prix, was handed his second practice appearance by Haas.

Dennis, in Verstappen’s Red Bull machine which Hamilton has described as the fastest ever seen in F1, finished 16th of the 20 runners, 1.1 secs off the pace.

O’Sullivan was 18th – seven tenths behind Williams’ Logan Sargeant – with Bearman 20th and last, albeit only a tenth slower than Kevin Magnussen in the other Haas.