Thomas Barr ran a season's best of 49.02 as he won the 400m hurdles in Gothenburg on Wednesday evening.
The Waterford man finished ahead of Sweden's Carl Bengtström in second and Johan Claeson in third.
The run was only Barr's second 400m hurdles race of the season. He finished seventh at the Diamond League meeting in Doha on Friday, running 49.91.
Barr looked comfortable through the race, particularly on the home straight as he pulled away from Bengtström.
"Now that’s more like it!" the 2016 Olympic finalist said on Twitter.
"That all important rhythm is back."
The time is 0.12 off the Olympic qualifying standard. However, even if he does not meet that standard, Barr is likely to qualify for Tokyo through the ranking system.
Thomas Barr wins 400m hurdles in Gothenburg
— PJ Browne (@P_J_Browne) June 2, 2021