In a tense final it was the English side who prevailed with a 2-1 victory to claim the silverware.
A frenetic first quarter saw the visitors in the ascendancy but the Harps rearguard held well with centre back Kevin Doherty marshalling his back four superbly.
The first chink in the armour came on the half hour mark after a fine save was parried by goalkeeper Ryan Brady for a corner.
The resultant corner saw Altrincham centre back Harry Dulson head goalwards with play waved on at first.
After consulting his line official, the referee awarded a goal claiming the ball had crossed the line.
Ten minutes into the second period, Harps conceded again.
Tricky Altrincham winger Thambani Jambaya neatly tucked the ball inside the post from 16 yards out to put his side 2-0 in front.
A constant barrage of attacks from the local side saw them pull a goal back when Caolan Kearney’s deft chip from 20 yards out deceived the keeper and crept under the crossbar.
Minutes later Harps went down to 10 men with Odhran Scarlett sent off for abusive language but this only spurred on his teammates who continued to apply constant pressure on the Altrincham defence.
Despite a number of close efforts in the dying minutes, the red and white of Altrincham ran out 2-1 winners and collected the Hughes Insurance Under 19 Foyle Cup at Ardmore from Mr. Don Brennan, Area Manager, Hughes Insurance Northern Ireland.
Meanwhile, it was an exciting day for local clubs with many Derry & District Youth FA (organisers) teams competing in finals.
Oxford United competed in the Under 9s, with Tristar, Oxford United (Under 13), Derry Colts (Under 14), Tristar (Under 15), Derry City and Trojans (Under 17) and Foyle Harps in the Under 19s.
At under 11 Dungannon Swifts won The Hughes Insurance Foyle Cup without losing a goal or dropping a point.
The Swifts entertained with not only their creative skills but also sporting behaviour.
Glentoran continued their fine tradition at the Foyle Cup with victory over Sion Swifts in an enthralling under 11 final.
The Glens have also booked their spot in the the Under 12 final after a convincing 2-0 win over Irish League opponents Ballinamallard United.
The east Belfast side have now made it to their third successive final and will defend their title at the Brandywell Stadium today with a 1pm kick-off.
Glentoran proved far too strong for everyone else in this age group.
They scored a total of 37 goals without conceding a single goal.
They brushed aside the challenge of Sheffield United in the quarter-finals with a 3-0 win. In the semi-final they looked assured with everyone of the starting 11 very comfortable in possession.
Glentoran play attractive football and supported by a large contingent of fans at Lisnagelvin, they made the task look easy.
Charlie Lindsay was prominent and will be the danger man as Donegal School Boys will look to nullify his passing skills in today’s showpiece final.
Donegal School Boys are equipped to deal with strength of Glentoran.
They have scored a total of 24 goals with 12 coming in their last two games.