MOTOR RACING: Russell suffers 'weird' crash as he struggles for speed

Formula One title contender George Russell said he was struggling for straight-line speed after suffering a 'weird' crash in qualifying at his home British Grand Prix on Saturday.

The Mercedes driver qualified only fourth while 19-year-old championship-leading teammate Kimi Antonelli secured pole position for Sunday's race at Silverstone.

Winner of the previous round in Austria, Russell has so far failed to carry the momentum over to Britain as Antonelli goes from strength to strength -- winning Saturday's sprint race and extending his championship lead to 43 points.

"I have raced here for 12 years and I have never locked up once in that corner before," said Russell of his excursion across the gravel and into the wall at Luffield.

"We made some changes to the set-up but it was probably more extreme than we thought. I don't know what happened. It was weird."

Russell managed to salvage his session to progress to the final top-10 shootout but Antonelli, in only his second season, always had the measure of him.

"This whole weekend we have been struggling with straight-line speed, we don't know why," the Briton told Sky Sports television.

"There is a couple of tenths over a lap, compared to all the other Mercedes (engined) cars, so I don't really know why that is. The team are working super hard to try and understand."

While the 28-year-old Russell suffered, Antonelli reaped the plaudits of pundits and team boss Toto Wolff.

The sprint win was his first in the shortened format and also the first since he went on a run of five grand prix victories in a row from China to Monaco -- a sequence Hamilton ended in Spain last month.

"It's impressive how he's calm and kills with a smile. It's a pleasure to watch," said Austrian Wolff. "There's no mistakes, he's really performing, considering it's his second year, at such a high level."

Jenson Button, Britain's 2009 champion with the Brawn team that became Mercedes, was also impressed.

"That was amazing, really impressive." he said after the qualifying session. "It feels like nothing fazes him."

-Reporting by Alan Baldwin; editing by Clare Fallon/Reuters