Lacey, the former Munster full-back/winger, made his debut for his home province as an 18-year-old in a friendly against South Africa's Transvaal back in December 1995. Most notably, he scored four tries in six Heineken Cup appearances for Munster.
He starred in the AIB League for Shannon, winning five AIB League and seven Munster Senior Cup titles, and has also played at club level for Sunday's Well and Clanwilliam.
A prolific try scorer, he touched down on 57 occasions in the AIB League.
Before his rugby playing career took off, he was a pupil of Abbey CBS in Tipperary town alongside Clanwilliam RFC's most famous son, Munster and Ireland flanker Alan Quinlan.
Having retired from playing rugby in 2007, he has made rapid progress from local level to international stage.
His refereeing days began in the Munster Schools Cup competitions, and this past season has seen appointed to some key European club games - six refereeing appointments in the Amlin Challenge Cup - and Magners League matches, as well as gaining promotion to the IRB Assistant Referee Panel.
Twelve months on from officiating at the IRB Nations Cup, the 36-year-old, who works as a Coach Development Officer with the Munster Branch, has impressed with his refereeing skills at the IRB Junior World Championship.
His performances in recent weeks are all the more remarkable, given that he was a late introduction to the referee panel in Argentina, following an unfortunate injury to English referee Greg Garner.
IRB Referee Manager Paddy O'Brien has labelled the standard of officiating at the tournament as 'up with the best' and a vital part of a referee's development.
"This tournament is hugely important for the development of a referee," explained O'Brien, who has seen Andrew Small, Keith Brown, Chris Pollock and Jerome Garces graduate from last year's Junior World Championship to the International Panel in 2010.
"All of them have had experience, whether it be at European or Super 14 level, but this is the opportunity for the IRB selectors to get a good look at them on and off the field and to give them work ons to go home with.
"History shows that the future IRB Panel referees come from age grade tournaments and clearly some of the referees here are international referees of the future."
Tipperary man Lacey, who was voted the 2009 Munster Rugby Referee of the Year, refereed the semi-final between defending champions New Zealand and South Africa in Rosario on Thursday and has obviously impressed O'Brien.
"In the selectors' view, there are four stand-outs at this tournament and the other four have performed well," added the New Zealander.
"So in the end, we had to go with those we believe have been the most consistent (for the semi-finals).
"We do not want the semi-final referees to change in any way their approach to the matches. They have been selected on the form they have shown to date and apart from modifying areas identified by the selection panel as weaknesses we ask them to referee the same as they have in the pool matches."
Irish rugby has a good track record of refereeing in IRB Junior World Championships. Lacey's fellow Munsterman, Peter Fitzgibbon, refereed the final of the inaugural tournament in Wales in 2008.
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