Donegal's Mark English has finished sixth in the men's 800m event at the Anniversary Games at the Olympic Stadium, London.
The Letterkenny man clocked a personal best time of 1:44.84 in the race, which was won by the US athlete Nick Symmonds in 1:43.67, a season best for the American.
English's time is significant as it is under the A standard for the upcoming World Championships in Moscow. The time was also the the joint-second fastest Irish 800m time ever, just behind David Matthews' time of 1:44.82, which was set in Rieti, Italy, on 5 September 1995.
The time was hugely significant for English as it means he has ducked under 1:45 for the first time ever in the 800m, and smahed his personal best by .48 seconds.
Earlier on in the evening, English's compatriot Rose-Anne Galligan finished sixth in the women's 800m at the Anniversary Games, clocking a national record time of 2:00.58. Laura Crowe failed to finish the same race; however, the Kerry woman was running as a pace maker for Galligan. American Brenda Martinez won impressively with a meet record of 1:58.19.
Galligan's new record erases O'Sullivan's time, which was set 19 years ago, by .11 seconds.
Galligan's time was her best ever run over the distance by .49 seconds and was the second time she has run the World Championships B time this season.
Both English and Galligan will feature at the National Track and Field Championships in Santry this weekend.
Bolt takes 100m in London
Rocket man Usain Bolt recovered from an awful start to light up the Olympic Stadium once again tonight as won the 100m in 9.85 seconds.
The Jamaican returned to the scene of his triple London 2012 triumph, but was made to sweat before blasting through to take the victory.
The 26-year-old entered the arena atop a missile for his customary lap of honour before the action, but this run hardly fired out a major statement of intent ahead of next month's World Championships.
It was still his fastest time of the year, though, and in the end he was a comfortable winner, with Mike Rodgers second in 9.98secs.