A Rob Manley double saw Longford Tow secure the league double over Shamrock Rovers II with a 2-1 win at Tallaght Stadium.
Longford Town created the three best chances of the first half while the home side were restricted to just one opportunity, which came in the early stages of the contest.
Rovers' winger Max Murphy cut in from the right letting fly from 25-yards, but Town stopper Lee Steacy made a comfortable save.
Town’s first chance came on 13 minutes, Town gaining possession on the edge of the Rovers' box, Dean Byrne played in Adam Evans who in acres of space 15-yards, scuffed his effort.
12 minutes later, Town midfielder Aodh Dervan capitalised on a mistake by John Ryan and released Rob Manley, Manley raced into the Rovers' box and squared the ball across to the unmarked Byrne, however, he completely miskicked his shot wide.
Longford eventually took the lead on 34 minutes, Rovers' centre-half Jordan Tallon's attempted clearance was blocked down by Byrne and Rob Manley was on hand to rifle a low, hard, diagonal 15-yard shot to the bottom right corner of the Rovers net.
The visitors doubled their advantage three minutes after the resumption, Rob Manley looping his header from an Evans free-kick past home keeper Kian Clarke into the net.
Rovers' got back into the game on 13 minutes from time, Town keeper Steacy could only push McMenamy's deflected shot into the path of substitute Kevin Zefi, and the fifteen-year-old blasted his shot into the top corner of net, becoming the youngest ever scorer in League of Ireland history.
Zefi almost equalised three minutes later with a 30-yard rocket that was tipped over the bar by Longford keeper Steacy.
This victory moves Longford Town up to second in the table just behind leaders Cabinteely on goal difference.
Shamrock Rovers II: (3-4-2-1) Clarke, Dunne (Emakhu 69), Tallon, Wells (Adigun 69), Murphy, Nugent, Bolger (McMenamy 55), Ryan (Omorehiomwan 55), Brennan (Zefi 69), Kavanagh, Leddy
Longford Town: (3-4-2-1) Steacy, McDonnell, Gorman, Joe Manley, Elworthy, Dervin, Zambra (Barnes 81), Evans (O'Brien 81), Grimes (McCabe 90), Byrne (Chambers 62), Rob Manley
Referee: Mark Moynihan