European champion Fionnuala Britton held off Britain's Gemma Steel to win the women's race at the Antrim IAAF International Cross Country event.
Steel, third behind Britton at last month's Europeans, bravely stayed with the Irishwoman over the opening two laps on Saturday before dropping back.
Britton pulled away in the closing stages to win by seven seconds with Ethiopian Birtukan Adama taking third.
Mike Kigen clinched his third straight men's win as Kenyans dominated.
Kigen, 25, finished 28 seconds ahead of his compatriot Patrick Mutunga with two more Kenyans Bernard Rotich and Yirsaw Tegegne third and fourth in the 10.8 kilometre race.
England's Frank Tickner was the best British and Irish finisher in fifth.
The Kenyan winner is hoping to challenge for a place in his country's marathon line-up for the London Olympics.
Joe McAllister and Breege Connolly were the first local finishers in the two races to land the Northern Ireland titles run concurrently with the races.
North Belfast runner Connolly was 13th overall as she finished 34 seconds ahead of Dromore's Julie Turley (16th) with North Down's Lauren Scott (17th) a further five seconds back.
McAllister was 12th man over the line to clinch the men's title, 10 seconds ahead of Andrew Agnew in 13th with Stephen Scullion 16th and Eddie McGinley 19th.