Thousands of people are sharing the €2.2bn (£1.9bn) prize pot in the world’s richest lottery.
At least 10 people will have shared the €4m ‘El Gordo’ jackpot, if they bought winning number 26590.
The exact number of winners won’t be known for a while as the tickets are divided into segments that allow people to buy a share of the prize winnings.
The winning number, worth €400,000 (£341,000) for each of the identical ten winning tickets, tumbled out of enormous metallic shuffling bins during a live televised event.
The winners won €20,000 (£17,040) for each euro spent on a €20 (£17) ticket.
El Gordo, meaning “the fat one”, is part of an annual Christmas lottery tradition – held each year on 22 December – that has a huge total prize haul, including lots of smaller prizes.
There are shares of a second prize of €1.25m (£1.07m), a third prize of €500,000 (£426,000) and many significant lesser amounts, with 9,999 tickets offering a prize of €200 (£170).
The winning tickets were sold in the north-eastern provinces of Tarragona and Barcelona, in central Madrid and Salamanca, and in southern Alicante, Murcia and Seville.
Children from Madrid’s San Ildefonso school announced the winning number during the draw at the city’s Teatro Real opera house.
Tiny wooden balls corresponding to the prizes roll down chutes from the two giant bins and are sung out by the youngsters during the three-hour gala.
Families, friends and colleagues buy tickets together as part of a winter holiday tradition.
They then gather around televisions, radios or mobile phones to follow the draw.
The national lottery was established as a charity in 1763 during the reign of King Carlos III. Its objective later became to shore up state coffers. It also helps several charities.