Kieran played the full 90 minutes as the host nation lost 1-0 to Greece at Windsor Park, Belfast. A first-half goal from Antonis Petropoulos did the trick for Greece in a close encounter in Group A.
Meanwhile, Phil was an unused substitute as England were held to a 1-1 draw by France in Group B. Abdoulaye Balde's equaliser cancelled out Matthew Fryatt's early effort for England.
The pair are back in action on Wednesday when Northern Ireland take on Serbia & Montenegro - who impressively beat Germany 4-2 in their opener - and England face Armenia. Both kick-off at 8pm.
The top two from each group go through to the semi-finals.
Phil Ifil and Kieran McKenna tasted disappointment in their opening games of the UEFA European Under-19 Championships in Northern Ireland.