Olasz, the silver medal at last year’s European Championships, was among the swimmers expected to be in contention to earn one of the final places on offer.

The Hungarian touched the finish in a time of 2 hours 1min 55sec to earn a second Olympic appearance, after competing at Rio 2016.

Spain’s Paula Ruiz and Canada’s Kate Sanderson finished two and three seconds behind the winner to seal their Olympic berths.

Britain’s Alice Dearing placed fourth in 2:02:01 to clinch her first Olympic berth, with home favourite Angelica Andre of Portugal fifth at the finish in 2:02.23.

Maria De Valdes finished sixth in the event but missed out on Tokyo 2020 due to being the second Spanish swimmer to finish, with only one spot available per nation.

Argentina’s Cecilia Biagioli, ROC's Anastasia Kirpichnikova and Ecuador’s Samantha Arevalo also finished in the top 10 to earn Tokyo 2020 quotas.

Slovenia’s Spela Perse, Japan’s Yumi Kida and South Africa’s Michelle Weber earned places at the Games.

Portugal’s Mafalda Rosa, Britain’s Danielle Huskisson and Hungary’s Reka Rohacs missed out due to being the second finisher from their nations.

Four continental quotas were earned by swimmers, with Venezuela’s Paola Perez and Ukraine’s Krystyna Panchishko earning the Americas and European spots respectively.

Singapore’s Li-Shan Chantal Liew and Algeria’s Souad Nefissa Cherouati secured the Asian and African spots.

The men’s qualifier is scheduled to take place tomorrow.