Francesco Bocciardo was among Para-swimmers to break world records on day one of the European Championships in Dublin's National Aquatic Centre.
The Italian, the reigning Paralympic S6 400 metres freestyle champion, broke his own record mark to win the 200m freestyle final in his new S5 division at the World Para Swimming-organised event.
He clocked 2min 23.65sec to better the 2:24:25 he managed last month,
Team-mate Antonio Fantin was second in 2:26.53 and Antoni Bertran of Spain third in 2:34.18.
Chantalle Zijderveld also improved on her own mark in the women's 100m breaststroke SB9.
She clocked 1:12.42, an improvement on her 1:13.77 set last year.
Lisa Kruger completed a Dutch 1-2 in 1:14.87 and there was bronze for Aliaksandra Svadkouskaya of Belarus in 1:26.43.
A third world record came in the women's 50m freestyle S6.
Ukraine's Yelyzaveta Mereshko won in 32.78 to erase the 32.98 clocking achieved by compatriot Viktoriia Savtsova in 2016.
Savtsova also went under the old mark in clinching second place today, just one hundredth behind the winner, as Great Britain's Maisie Summers-Newton took bronze in 34.70.
Action will continue tomorrow.