The race had to be restarted after Zhou’s car overturned and crashed into a fence after being cut off shortly after the start.
This caused a long delay, but the driver was eventually cleared after being assessed at the medical center.
After the race restarted, Red Bull drivers Max Verstappen and Sergio Perez suffered damage to their cars and dropped out of the pecking order allowing Ferrari’s Sainz and Charles Leclerc to establish a solid lead.
But a safety car with 10 laps to go got Perez back in touch and he and Lewis Hamilton passed Leclerc in a thrilling finish to secure second and third place respectively.
Sainz, who had also passed his team-mate after the safety car, struggled to contain his emotions after crossing the line first.
“I don’t know what to say, it was amazing,” Sainz said emotionally after the race. “It was a very special day that I will never forget.
“It wasn’t easy, I struggled a lot with the balance […] but even with all that, I remained a believer.”
There was plenty of pre-race excitement with a plethora of world stars busy on the grid before the start.
Shortly into the race, however, that excitement turned to nerves after the huge collision brought proceedings to a halt on the first lap.
Footage showed Zhou’s Alfa Romeo overturning in a dramatic incident which also involved George Russell and Pierre Gasly.
Zhou’s car skidded upside down on the track, then knocked over the tire barrier before crashing into the fence.
During a nervous wait for news, doctors attended to the Chinese driver and he was eventually carried into an ambulance after avoiding serious injury.
Williams Racing driver Alex Albon, who was involved in another crash following the incident, was taken to hospital in Coventry for precautionary checks.
After a long wait, the race was restarted with a standing start in the original grid positions – despite Verstappen overtaking Sainz on the first start and Hamilton’s initial jump from fifth to third.
The reboot was clean but not without drama. The Ferrari and Red Bull cars battled it out for the top four spots, with Perez sustaining damage to his car and falling back into the field after a forced pit stop.
Sainz did well at first to hold off Verstappen, but the Red Bull driver quickly overtook and took a familiar lead.
However, it wasn’t long after the reigning F1 champion appeared to have a puncture and suffered damage to the rear of the car.
After a pit stop and with his performance hampered, his race was effectively over to the delight of some at Silverstone who had mocked the driver over the weekend.
When it looked like the two Ferraris were going to run flawlessly, the safety car regrouped the field again, allowing Perez and Hamilton to fight their way to the podium.
Sainz hopes to follow up his first victory in the sport with another in Austria next week.