Fionnuala McCormack (née Britton) has comfortably achieved the qualifying standard for the Rio Olympics with a 13th place finish at the Chicago Marathon.
The Wicklow woman finished in a time of 2:33:15, almost nine minutes inside the qualifying time of 2:42.
The race was won by Florence Kiplagat, world record holder for the half marathon, in a time of 2:23:33.
Kiplagat's Kenyan compatriot Dickson Chumba won the men's race in 2:09:25 as the Kenyan completed a clean-sweep of the men's podium places.
Lizzie Lee of Leevale has already achieved the standard when she ran a 2:32:51 at the Berlin Marathon in September.
Breege Connolly of North Belfast Harriers has also achieved the standard, while Maria McCambridge will be hoping to make it a quartet of Irish women with the mark when she runs in Frankfurt later this month.
McCormack, who made her mark on the cross-country scene, is forgoing the mud in order to focus on the marathon in Brazil.
McCormack ran in the 3,000m steeplechase in Beijing in 2008 and did a 5,000m/10,000m distance double in London in 2012.