Martina Sáblíková won her 14th gold medal at the World Single Distances Speed Skating Championships as this year's event began in Inzell in Germany.
The Czech won the 3,000 metres title for a fifth time at the Max Aicher Arena, setting a track record of 3min 58.911sec.
It means yet another prize for the 31-year-old, who is also a triple Olympic champion and a four-time winner at the World Allround Championships.
Double Olympic medallist Antoinette de Jong won silver in 3:59.411 as Russia's Natalia Voronina took bronze in 3:59.992.
"When I crossed the line and saw that number one behind my name..." Sáblíková said afterwards. “
"Last season I considered quitting speed skating.
"This is amazing."
Day one also saw a maiden major individual title for Norway's Sverre Lunde Pedersen in the men's 5,000m.
The Olympic team pursuit champion from Pyeongchang 2018 clocked a track record and personal best of 6:07.167 to finally top the podium after six minor medals at World Championship level.
Dutch skaters came second and third as the speed skating powerhouse missed out on an individual gold on the first day.
Reigning world allround champion Patrick Roest clinched silver in 6:11.700 as the legendary Sven Kramer had to make do with bronze.
Kramer, a four-time Olympic champion who boasts 28 world titles, clocked 6:12.531 and could not add to his Pyeongchang 2018 gold over the distance.
It also means his 100 per cent record in the 5,000m at this Championship is now at an end.
"The perfect race? This might have been it," Pedersen said.
"I thought maybe it was too fast, but it was easy to keep my speed and stay strong."
The Netherlands did seal both team sprint titles today in Inzell.
Ronald Mulder, Kjeld Nuis and Kai Verbij won the men's in 1:19.05, getting the better of South Korea's Cha Min-kyu, Kim Jun-ho and Kim Tae-yun who timed in at 1:20.00.
Russia's Pavel Kulizhnikov, Ruslan Murashov and Viktor Mushtakov stopped the watches at 1:20.10 for bronze.
Letitia de Jong, Jutta Leerdam and Janine Smit sealed the women's team sprint title for the Dutch, ending in 1:26.28.
Canada's trio of Kali Christ, Kaylin Irvine and Heather McLean took silver in 1:27.21 as Russians Olga Fatkulina, Angelina Golikova and Daria Kachanova clinched bronze in 1:27.26.
Sprint titles will be decided tomorrow with the 500m held for men and women.
Medals will also be up for grabs in the team pursuit.