Ciara Mageean ran a brilliant personal best of 4:19.03 in the women's mile at the Monaco Diamond League on Friday night and clocked the 1500m Olympic qualifying standard in the process.
The Portaferry woman shaved over three seconds off her previous PB to finish eighth in a red-hot race in which the winner, Sifan Hassan of the Netherlands, set a new world record of 4:12.33.
Sonia O'Sullivan still holds the Irish record of 4:17.25.
Mageean, 27, secured the Olympic standard at the 1500m split with a time of 4:01.21, well inside the required 4:04.20.
She won a bronze medal earlier this year at the European Indoor Championships in the 1500m, but the main target for this season remains the IAAF World Championships which begin on 27 September in Doha.
Hassan meanwhile shattered the 23-year-old women's mile world record in a race dedicated to former American runner Gabe Grunewald, who died from cancer last month at the age of 32.
Hassan, 26, initially looked to be off the record pace in the rarely-run event but finished strongly to edge the 4:12.56 set by Russia’s Svetlana Masterkova in Zurich in 1996.
It was a fitting performance in an event named the 'Brave like Gabe' Mile. There was a tribute to Grunewald on the big screens at the stadium before the race and once it was underway, Hassan, who moved to the Netherlands after leaving Ethiopia as a refugee when she was 15, was always in control.
"I knew I could run fast, but the first 800 was a bit slow, so after that I wasn't thinking it would be a world record," said Hassan, who took more than two seconds off her previous best for the distance.
"When I crossed the line I was so surprised," she added after clocking a 62 seconds final lap.
"After you run the last 400 like that, and set a world record, it gives you so much confidence over 5,000m.
"I want to double over 1500 and 5,000 in Doha (at the world championships in September) and the way I finished the last 400, it's amazing."