The race had to be restarted after Zhou’s car was flipped upside down and crashed into a fence having been clipped shortly after the start.
It caused a lengthy delay but the driver was eventually declared fit after being assessed at the medical center.
After the race restarted, Red Bull drivers Max Verstappen and Sergio Perez sustained damage to their cars and dropped down the pecking order allowing Ferrari’s Sainz and Charles Leclerc to establish a strong lead.
But a safety car with 10 laps to go allowed Perez to get back in touch and both he and Lewis Hamilton overtook Leclerc in an exhilarating end to the race to secure second and third respectively.
Sainz, who had also overtaken his teammate after the safety car, struggled to hold back his emotions after crossing the line first.
“I don’t know what to say, it was amazing,” an emotional Sainz said after the race. “It was a very special day that I will not forget.
“It was not easy, I struggled quite a bit with balance […] but even with all that I stayed believing.”
Horror crash
There was plenty of excitement ahead of the race with a plethora of global stars busying the grid before the start.
Shortly after racing began, however, that excitement turned to nerves after the huge collision stopped proceedings on the first lap.
Footage showed Zhou’s Alfa Romeo flipping upside down in a dramatic incident that also involved George Russell and Pierre Gasly.
Zhou’s car skidded upside down across the track and then flipped over the tyre barrier before crashing into the fence.
During a nervy wait for news, medics tended to the Chinese driver and he was eventually stretchered into an ambulance having avoided serious injury.
Williams Racing driver Alex Albon, who was involved in a separate crash as a result of the incident, was taken to Coventry Hospital for precautionary checks.
After a long wait, the race began again with a standing start in the original grid positions — that was despite Verstappen overtaking Sainz during the first start and Hamilton initially jumping from fifth to third.
The restart was clean but not without drama. The Ferrari and Red Bull cars battled each other for the top four positions with Perez sustaining damage to his car and falling back in the field after a forced pitstop.
Sainz initially did well to hold Verstappen off but the Red Bull driver soon overtook and stretched into a familiar lead.
However, it wasn’t for long after the reigning F1 champion appeared to get a puncture and suffered damage to the car’s rear.
After a pit stop and with his performance hampered, his race was effectively over much to the delight of some at Silverstone who had jeered the driver over the weekend.
When it looked as though the two Ferrari’s would race clear, the safety car bunched the field back up again allowing Perez and Hamilton to fight their way onto the podium.
Sainz will hope to follow up his first win in the sport with another in Austria next week.