This is the dramatic moment a security guard in Beijing suddenly collapses and goes into convulsions – before a heroic doctor rushes to his side and gives him CPR.

The mask-wearing man is seen falling backward, the back of his head hitting a car, the Newsflare video shows.

A few seconds later, the woman – a doctor named Zhu Haoyu – jumps out of a vehicle down the road, runs over to the man, rolls him over onto his back and starts performing chest compressions.

As she is about to give him mouth-to-mouth respiration, the guard appears to regain consciousness and he reaches around her shoulder.

An ambulance then arrives and paramedics whisk the man to a hospital.

Zhu, who practices in Jilin Province, is conducting postdoctoral study in Beijing, according to reports.