Published Saturday, 31 May 2014
Uruguay's Christian Stuani celebrates after scoring against Northern Ireland (© Getty)
Uruguay were lacking Liverpool star Luis Suarez, who says he will be fit to meet Group D opponents England in Brazil next month.
Northern Ireland lie 78 places behind the South American side in the FIFA rankings but exceeded expectations during the friendly encounter at Estadio Centenario.
They stood firm against their opponents' weight of possession - with only a solitary second-half strike from substitute Christian Stuani making the difference when he finished from close range in the 62nd minute.
O'Neill said he was proud of his team's battling effort in front of almost 60,000 fans.
The manager, who has been denied the services of senior players such as Jonny Evans, Gareth McAuley, Chris Brunt and Martin Paterson in South America, handed debuts to Luke McCullough, Paul Paton and Ryan McLaughlin.
"The lads on debut were a credit (...) and right through the team the application was first rate," he said after the match.
It's an extremely young squad and we couldn't ask any more on the night against top-class opponents who are heading to the World Cup.
"The most pleasing thing for me is the lads really seemed to enjoy the challenge," O'Neill added.
"I thought they were excellent and at times our possession of the ball was superb.
"Steven Davis was immense - as good a performance as he's had under me - and Sammy Clingan and Oliver Norwood too.
Following his side's narrow defeat, O'Neill tipped England to beat Uruguay in Sao Paulo on 19 June.
"Having seen Uruguay, I would expect England to beat them in Brazil," O'Neill added.
"I think if England play with pace in the forward areas they will cause them real problems
"I'll be honest, I think you can get at them," he told English reporters.
O'Neill revealed he had not been in contact with manager Roy Hodgson prior to the fixture, but would be happy share any observations if the call was made.
"I haven't spoken to Roy in the build-up but if he wanted to call me or my assistant Billy McKinley, who he worked with at Fulham, there'd be no problem there.
"But I'm sure he doesn't need to, they will have had someone here and there'll be a dossier 250 pages thick."
Northern Ireland will conclude their South American tour when they face Chile in the early hours of Thursday morning.
© UTV News