Officers attempted to block the vehicle, then fired shots with Tasers and live bullets after the Mercedes again drove into Galibarenko's auto - and also into police - at about 10am yesterday.
The embassy said in a statement that the ambassador's empty official vehicle had been deliberately rammed as it sat parked in front of the building. No one was injured, it said.
The embassy identified the auto as the ambassador's official vehicle, and said it had been parked in front of the diplomatic post.
The man was taken to hospital as a precaution but was not injured, they added.
It is not known if the man in the auto was wounded, but he was eventually removed from the vehicle and detained by police.
A woman who works at a nearby shop told the Press Association she heard shots fired twice between 10:00 GMT and 11:00.
The woman, who did not wish to be named, said officers arrived "very quick", adding: "I saw many police cars coming". Police say the vehicle "was driven at police officers," per the Guardian. It added that British police were investigating the suspect's identity and a possible motive.
TV footage later showed a silver auto slewed across the cordoned-off road with its driver's door open and window shattered.
The Metropolitan Police confirmed armed and unarmed officers were dispatched to the incident, and that a Taser was also used.
London police say the Saturday morning incident is not ongoing.
"While this takes place, I would like to pay tribute to the officers involved this morning who responded swiftly to this incident and put themselves in harm's way, as they do every day, to keep the people of London safe".