Russia reported 9 623 new coronavirus cases - its highest daily rise since the start of the pandemic - bringing the total to 124 054, mostly in the capital Moscow.
The death toll nationwide rose to 1 222 after 57 people died in the last 24 hours, Russia's coronavirus crisis response centre said on Saturday.
Concern was growing in Moscow that hospitals might become overwhelmed after recording the new one-day high of infections, a 20% increase over Friday's count, which itself was a new daily record.
Despite lockdown measures, infection numbers have been rising at an alarming rate for days in the world's largest country by area.
Moscow is the worst-affected part of Russia, accounting for about 62 600 cases, about half of the nationwide total.
People there who have not obtained a special permit for free movement are only able to leave their homes to shop, walk their dogs, and dispose of rubbish.
President Vladimir Putin has ordered the restrictive measures, called non-working days, to continue until May 11 when the country finishes celebrating the Labour Day and Victory Day holidays.
Despite a relatively low number of cases and deaths compared with the United States, Italy and Spain, which have been hit hardest by the disease, Russia's infection curve has not reached a plateau.
Real number infected
Moscow Mayor Sergey Sobyanin warned the Russian capital was not yet past the peak of the outbreak.
"The threat is apparently on the rise," Sobyanin said in his blog, adding that 2 percent of the Moscowvite population - or more than 250 000 people - is believed to have contracted the virus.
"According to screening tests of various population groups, the real number of the infected is around two percent of Moscow's total population," Sobyanin said.
Sobyanin told Rossiya-1 TV station that, should the situation worsen, authorities may cut the number of digital permits issued for travel across the city.
He said Moscow had significantly ramped up testing capacity, adding that the city has managed to "contain the spread of the infection" with the enforcement of stay-at-home rules and other measures.
Moscow's mayor said this week officials are considering establishing temporary hospitals at sports complexes and shopping malls to deal with the influx of patients.
Top officials infected
Infection cases have reached the highest levels of government.
Prime Minister Mikhail Mishustin, the second-most senior official in the country after Putin, told the president on Thursday that he tested positive for coronavirus and was temporarily stepping down to recover.
First Deputy Prime Minister Andrei Belousov is now serving as acting prime minister in his absence.
On Friday, another member of the Russian cabinet, Construction Minister Vladimir Yakushev, announced he was diagnosed with the virus and would be treated in hospital. Dmitry Volkov, one of his deputies, also tested positive, the ministry said.
Covid-19 has killed more than 238 000 people worldwide, including more than 65 000 in the United States and more than 20 000 each in Italy, the United Kingdom, France and Spain, according to a count kept by Johns Hopkins University.
Health experts warn a second wave of infections could hit unless testing is expanded dramatically.