National cross-country champion Mark Christie of Mullingar Harriers and Newcastle's Kerry O'Flaherty were the winners at the National 10k, held in Dublin's Phoenix Park in conjunction with the Great Ireland Run.
In the men's race, Christie proved the class of the field, winning in 29 mins 30 secs, and beating British guest Graham Rush who finished in 29:41.
Raheny's Mick Clohisey was a close third and second in the National Championships in 29:44 - an improvement on his time of last year of 30 minutes exactly when he finished second overall.
The top three were all quicker than last year on the tricky course.Sergiu Ciobanu of Clonliffe was third in the National Championships in 30:20.
Defending champion Fionnuala McCormack's late withdrawal from the women's race left the way open for Olympic steeplechaser O'Flaherty to take the national title in 34 mins 38 secs. Overall she finished third behind British visitors Gemma Steel in 34:15 and Jenny Spink in 34.24.
Leevale's Clare McCarthy was fourth overall and second in the National Championships in 34:47 while taking national 10km bronze was Laura Shaughnessy of DSD in 35:06.
Winning the women's team title for the first time were Catherina Mullen, Kate O'Neill and Sarah Fay of Metro St Brigid's, with Mullen leading them home in seventh th place.
Raheny won both senior and M35 titles, with Mick Clohisey, Kevin Dooney, Simon Ryan and Donal Foley making up the senior team and John Dunne, Michael McMahon and Ciarán McCarthy the winning M35 trio.
Tallaght's Niall Coppinger, Gerard Dore and Dave Meehan combined to win the M50 team title - up from fourth last year.
First of the W35 teams was the Donore Harriers trio of Aislinn Nic Dhomhnaill, Bronagh Elliott and Karla Doran.
Retaining their W50 title were Mayo AC's Angela O'Connor, also first W50, Pauline Moran, second W60 and Margaret Glavey first W65.
At the TQ 10km in Belfast, the women's times on a flatter course were faster than in th Park, with QUB's Emma Mitchell winning in 34 mins 5 secs after an early battle with national marathon champion Laura Graham of Mourne Runners.
Graham finished second place in 34:27 with Amy Bulman third in 37:25. Overall winner of the race was Dromore's Russell White n 31 minutes 35 seconds with Chris Madden only three seconds behind for second and Conor Duffy of Glaslough third in 31:45.