Irish Olympic boxing medallists Wayne McCullough and Michael Carruth took part in an early morning handover ceremony on Wednesday.
It was witnessed by Games chief Lord Sebastian Coe at a remote spot bordering Newry, Co Down and Dundalk, Co Louth.
Mr McCullough said: "I am from the Shankill Road in Belfast, I have never had any problems like religion.
"It is a major step for everybody, people are coming together.
"Boxing was always a sport where Protestant and Catholic came together."
Crowds of local people watched and cheered as McCullough, who won bantamweight silver in the 1992 Games, passed the flame to Carruth, who took welterweight gold in the same tournament.
Mr McCullough, who lives in Las Vegas, said he carried the Irish tricolour in the 1988 Olympics in Seoul and said it had been 24 years since he saw the flame.
"It is pretty awesome," said the boxer. "This was something I was looking forward to all week, to do something cross-community and meet my good buddy Michael Carruth.
"It is a once in a lifetime opportunity and I am honoured to be doing it.
"It was like going into the Olympic final again, you get emotional, it was almost like I was about to fight again."
The pair's meeting point on the old Dublin Road was a far cry from the bright lights of Seoul - this time they had a disused shed for a backdrop with a green hill in the distance.
Mr Carruth said: "It is fantastic, the torch is what is good about sport.
"It is a fantastic occasion for everyone, north and south of the border."
Dubliners lined the streets of the capital as the torch toured the only city outside the UK after special permission was granted.
President Higgins and Taoiseach Enda Kenny both greeted the relay team, which took in several of the city's historic sites, including the GPO, Trinity College and Croke Park.
Pop stars Jedward - also known as brothers John and Edward Grimes - carried the flame along O'Connell Street and past some of the city's most famous landmarks.
Thank you, guys, so much for all coming out and being so Jepic and so Jedicated to the Olympics. Last year we had Barack Obama and this year we have the Olympic Torch.
"It's such a great experience being here," said John. "It was such an honour to carry the Olympic Torch in the relay.
Edward added: "We're so excited to be here. The Olympic Torch is so symbolic, you better be watching the Olympics.
"Go, Team Ireland!"
Jockey Ruby Walsh, former footballer Paul McGrath and Olympic winning runners Sonia O'Sullivan and Ronnie Delany were also among the 41 torchbearers taking part in the relay.
Taoiseach Enda Kenny welcomed the flame at Government Buildings, which was visited by Queen Elizabeth during her landmark tour of the Republic last year.
"The symbolism is so powerful," said Mr Kenny. "It epitomises in so many ways what the Olympics actually stand for - higher, faster and stronger - for all of those young people who can be inspired by sport, that they take up to become world champions.
"It's an enormous commitment for split-second timing to be the best in the world and to achieve Olympic glory and therefore, like Ronnie Delany, everybody knows him because of his achievements in 1956.
"On behalf of the people of this country, it's great to have the Olympic flame come through."
The Olympic Torch started its tour of the island when it arrived in Belfast on Sunday, with 400 torchbearers taking part in a five-day relay around Northern Ireland.
It later returned to Belfast for a run around the city and evening celebrations at City Hall.
On Thursday, the torch will travel to Newcastle, Dundrum, Clough, Downpatrick, Crossgar, Saintfield, Ballynahinch, Templepatrick, Antrim, Ballyronan, Magherafelt, Ballymena and Moorfields before leaving for Scotland on Thursday night.
The torch will arrive in London next month as the highlight of the opening ceremony of the 2012 Olympic Games.