'Mike' took first place, while 'Finn' was runner-up, beating off competition from 18 of the UK's most skilled police dogs.
Over the past three days they were taken through a variety of scenarios reflecting the work they and their handlers experience in real life.
Tests covered everything from chasing and detaining a criminal armed with a gun to searching for an item in a property, as well as obedience and agility skills.
The last time a PSNI dog won the UK-wide tournament was 11 years ago.
Mike and Finn's handlers were stunned at this weekend's achievement.
The dogs live permanently with their handlers and form a close bond with them.
"This is hard to believe," said handler Constable McCrea.
He said Mike was his first police dog.
"They trained me as a handler at the same time," he said.
He added that it showed how comprehensive the PSNI dog training was.
"We had good support from the training team and we have to put the training in ourselves," he said. "I am shellshocked to win."
Constable Bradley said he got Finn as a nine-month-old pup.
"I brought him on for six or seven months before he completed the general purpose training in 2013 and he has been operational for three years," he explained.
"We've had quite a few successes in that time.
"This is like the golf Open for anybody that has an interest in training and working dogs - these are the UK's best dogs.
"This result goes a long way to showing the dedication, commitment and professionalism by the dog handlers, the dogs and the support team.
"It's like having Northern Ireland winning the World Cup and coming runner-up as well. It never happens. In 56 years this is the first time."
Superintendent Nigel Goddard said the dogs showing off their skills yesterday were the best of the best, and described Mike's round as flawless.
"Our trained dogs play an important role within policing by supporting officers in a number of ways, including finding missing people, locating illegal drugs, cash and explosives, controlling crowds, searching cordon points and public venues, as well as tracking down criminals who attempt to get away," he said.
"The National Trials provide a platform to showcase the expertise, skills and abilities of handlers and their canine colleagues from across the UK.
"They also provide the public with a glimpse into the significant contribution they make daily in protecting people and communities."