Authorities in Moscow registered 9,120 cases on Saturday - the highest number since the start of the pandemic. The previous high had been reached the day before with around 9,000 infections.
According to Mayor Sergei Sobyanin, almost 90 per cent of Covid-19 cases are now due to the particularly infectious delta variant that was first detected in India.
Moscow - like all of Russia - has seen its efforts impeded by a large amount of vaccine skepticism among the public.
Half a year after the start of mass vaccinations, only about 15 per cent of the 12 million residents of the capital have been vaccinated with one of the Russian-made jabs.
Across Russia, about 11 per cent have been fully vaccinated, according to data released on Friday.
Moscow tightened coronavirus restrictions once again in light of the dramatic spike in cases.
Large events, for example, were limited to 1,000 people and the fan zone for the Euro 2020 football championship was closed.
In addition, a number of companies have been required to enforce a 60 per cent vaccination quota among their employees.