It was not long, however, until the American side responded with a try by scrum half Chris Saint, converted by Cowley.
Two penalty kicks ensued and the All-Americans pushed into the lead. Leader brought it back with his first penalty of the game but with only 11 minutes to go, the All Americans' fourth successful penalty brought their side to the fore where they remained until the final whistle, despite intense pressure from Connacht.
The final score was 19-17 to the visitors. Connacht Academy manager Nigel Carolan said: "The game was a great opportunity for some of the younger development players to get a run-out early on in the season. It also gave the coaches a chance to look at players ahead of the British & Irish Cup.
"The US team proved to be formidable opposition but this was a worthwhile run out for the Development side. We look forward now to meeting Munster next week."
The Connacht Development players will face Munster 'A' at the Sportsground on Thursday, August 23.
The British & Irish Cup kicks off during the second weekend in October with the Connacht Eagles' first pool game against Newport at Rodney Parade.