Trailing 3-1 after the morning foursomes, Connacht won the last three matches of the day to take the spoils.
Wesport’s Harry Gillivan clinched a crucial one-hole win in the penultimate match to turn the tie with wins also for Jack Tuohy (Galway Bay), Allan Hill (Athenry), and David Kitt (Athenry).
Leinster were comfortable winners against Munster, securing a 7.5-2.5 verdict. Munster held their own in the foursomes, halving the two top matches, although Leinster went ahead when Jack Doherty and Charlie Denvir combined for a 3&2 win. Leinster took control in the singles, winning five of seven matches. Denvir was most impressive, romping to a 7&6 success at the bottom of the order.
Leinster now play Ulster on day two while Connacht square off against Munster.
In the U14 championship, Leinster are in pole position after winning both matches on the opening day.
Joseph Byrne won the decisive singles point to secure a 3-2 win against Connacht while Alex Bolger and Liam Abom were victorious in the singles during a 3.5-1.5 win against Munster.
Ulster beat Munster 3.5-1.5 in the first match of the day but went down to Connacht in the afternoon, 3-2.
The U14 championship concludes today with Leinster up against Ulster while Connacht play Munster.
The U16 championship also gets under way today. First out are Munster and Ulster with Connacht playing Leinster.