Zhou Guanyu hailed Formula 1's "halo" system and the rapid response of the rescue team for saving his life after the Chinese driver was involved in a frightening first-lap crash at the British Grand Prix on Sunday.

"It was a big crash and I'm glad I'm OK. The marshals and the medical team at the track were fantastic with their quick response, and I also owe thanks to the FIA and Formula 1 for all the work they have done," said the Alfa Romeo rookie.

"They are constantly improving the safety of our cars. The halo saved me today, and it goes to show that every step we take in improving our cars has real, valuable results."

On Saturday, Zhou had impressed in British GP qualifying as he battled the weather conditions to claim another Q3 and start ninth on the grid on Sunday.

The race got off to the scariest possible start at Silverstone when Zhou, Mercedes' George Russell and AlphaTauri's Pierre Gasly collided causing Zhou to barrel out of the race, while Williams' Alex Albon was caught up in an incident involving AlphaTauri's Yuki Tsunoda, Aston Martin's Sebastian Vettel and Alpine's Esteban Ocon.

Zhou's Alfa Romeo slid upside down across the gravel and was wedged between fencing and a tire barrier at the first corner. Zhou was saved by the car's halo, which prevented his head from hitting the ground as the car overturned.

The race was instantly red-flagged as rescuers rushed to the scene. Russell also sprinted from his car to the tire barrier to check on Zhou.

Zhou and Russell both spent time in the medical center before being getting the all-clear. Albon was transferred by helicopter to Coventry Hospital for "precautionary checks".

"We started on the hard tires because I made a mistake in qualifying and we thought that risk gave us the best opportunity later in the race, but there was just very little grip at the start," explained Russell.

"It's the hardest compound, it's cold out there and I got swamped by all the cars. Next thing I know I got touched, I was into the side of Zhou, and that was it. I jumped out to see if Zhou was OK and I saw it was red-flagged straightaway.

"It was obviously frustrating for my race because the car just had the puncture and there's no doubt we had the pace to come back to P6 today, but I'm just glad that Zhou was OK."

As closeup replays of the accident were not immediately available, shocked fans back home had to wait anxiously for an update on Zhou's condition.

So, there was an enormous sense of relief when the sport's governing body, the FIA, advised that the drivers were conscious and being evaluated. The FIA later announced that Zhou was "in good health" and had left the medical center.

"I think we can all agree that the most important thing today is seeing Zhou come out of such a huge crash without any injury. What we witnessed were dramatic scenes, and once again we have to thank the great improvements in safety spearheaded by the FIA and Formula 1 for a positive outcome," said Frederic Vasseur, Alfa Romeo's team principal.

"The work to improve safety in our sport is never done and today reminds us of just how important this is. Zhou is OK and fit to race in Austria next week, and this is the big victory of the day."

When the race eventually resumed, Ferrari's Carlos Sainz took the checkered flag in first.

Earlier on Sunday, the halo device saved Roy Nissany from serious injury in the Formula 2 race when Dennis Hauger's car landed on top of the Israeli's cockpit. Hauger also escaped unhurt.

Last season Lewis Hamilton was grateful for the halo when Max Verstappen's Red Bull ended up on top of his cockpit in a scary incident at Monza.

"First and foremost, the main thing today is that Zhou is fine. It was a big shunt, and I'm glad that nothing serious happened and that he has already been cleared by the FIA. Today, we got additional proof on how the halo is one of the greatest innovations in F1, and how safety has improved in recent years," said Zhou's Alfa Romeo teammate Valtteri Bottas, who retired with gearbox issues.

The Canadian GP late last month marked the first time that Zhou made it through to Q3 in qualifying, and he eventually finished eighth to earn four precious points.

"Qualifying was a challenge, but I would say I didn't do too bad for a rookie! It was my first time driving in F1 in Silverstone in the wet," said Zhou after qualifying.

"It feels amazing to score back-to-back Q3 appearances," the 23-year-old added. "I feel like I'm growing as a Formula 1 driver and I am really happy about that."

Remarkably, Zhou is already looking ahead to the next grand prix. "I'm keener than ever to get back on track and do what I love," he said. "I'm fit and I'm looking forward to Austria next week."