Russian state-controlled gas giant Gazprom said it was pumping record volumes to Europe amid unusually cold temperatures.
The January 7 announcement underscored the degree to which many European countries remain heavily dependent on Russian supplies.
Gazprom said in a statement that the daily volume on January 6 exceeded its previous record, set one day earlier, by nearly 1 million cubic meters. Most of that is delivered through the Nord Stream pipeline under the Baltic Sea.
The state-controlled company delivers about one-third of the European Union's natural gas.
EU countries, led by Germany, have sought to diversify their energy supplies away from Russia, as political tensions continue.
Supplies were interrupted midwinter in 2005 and again in 2009 after a price dispute with Ukraine. That led to the construction of Nord Stream, which bypasses Ukraine and goes directly to Germany.
Moscow's annexation of Ukraine's Crimean Peninsula in 2014 sent relations with the West spiraling to new lows.