Belgium got in front on 12 minutes following a sweeping counter-attack.
A cross from the left fell to captain Youri Tielemans 20 yards out and the Anderlecht midfielder found the top corner with a rising shot.
Jesse Devers went close to equalising 18 minutes later when he latched onto Jack Tuite’s through ball only to send his low effort a yard wide.
Ireland battled gamely in the second-half and drew level from the penalty spot eight minutes from time.
Devers was brought down by Nathan Leyder and Irish captain Dan Casey sent Quintjin Steelandt the wrong way.
Six minutes later, Shane Elworthy had a chance to seal the win for Ireland when Devers sent him clear but the winger flashed his effort wide.
The nations meet again tomorrow, also at the home of Killarney Celtic (11am).
Meanwhile, Harry Kenny’s Irish U17 women recorded a 2-0 victory over Belgium yesterday in Liege.
Katie McCabe and Amber Barrett provided the goals in the first of this week’s double-header, the final workout before the UEFA elite qualifiers in Norway from March 19-24.
IRELAND: J Talbot (Home Farm); J Tuite (Cherry Orchard), S Whelan (Lourdes Celtic), D Casey (St. Joseph’s Boys), A Breslin (St. Kevin’s Boys); R Purdy (St. Kevin’s Boys), C Melody (Mervue United), C Fogarty (Woodlawn); S Elworthy (St. Kevin’s Boys), J Devers (Manulla), S Byrne (St. Joseph’s Boys)
Substitutions: D Tobin (St. Kevin’s Boys) for Purdy, C Deasy (Malahide Unite) for Fogarty, M Benrouggibbi (St. Joseph’s Boys) for Tuite (all 43 mins), D Kane (Cherry Orchard) for Whelan, E Osam (St. Kevin’s Boys) for Byrne (both 49 mins), C Coleman (Kilreen Celtic) for Breslin (54 mins). BELGIUM: Steelandt; Desaever, Leyder, Delhounge, Konsiembo, Vlietinck, Meyssen, Holly, Kerstenne, Tielemans, Callebaut.
Referee: Kevin O’Regan (Kerry).