Shane Moran and Jack Heslin's goals ensured victory for Leitrim in the Tailteann Cup at Carrick-on-Shannon and sent favourites Antrim home empty-handed.
After Odhrán Eastwood put Antrim ahead with an opening minute point, Leitrim hit back with three on the trot during the next seven minutes with Keith Beirne getting two and David Bruen chipping in with one.
An 11th-minute Jamie Gribbin point reduced Leitrim's advantage to the minimum. But Leitrim surged ahead again over the next four minutes with points from Jack Heslin and Beirne.
Leitrim had a let-off shortly after when Eastwood drove a clear cut goal chance wide. However, four minutes later Antrim's Patrick McBride kept the Glens Men's hopes alive when he fired over.
But the tide then turned in Leitrim's favour when Moran flicked a long ball in from midfield into the Antrim net.
Leitrim continued to drive home their advantage with Cillian McGloin, Heslin, Beirne (free) and Donal Wrynn (mark) putting over points each by the 32nd minute.
Antrim's Dermot McAleese blazed a goal chance over prior to the break, which left Leitrim with a comfortable 1-10 to 0-4 interval lead.
Antrim reduced the deficit after the restart when full-back Peter Healy - switched up front at half-time by the Saffron's manager Enda McGinley - hit a 38th-minute point.
But two minutes later Heslin palmed home a Leitrim goal, which certainly put Andy Moran's men in the driving seat. Pearce Dolan stretched with Leitrim advantage with another point.
Antrim replied with a Pat Shivers almost immediately but Evan Sweeney hit back with a similar Leitrim score within the space of three more minutes. Antrim's Ruairí McCann and Leitrim's Jordan Reynolds swapped points at opposite ends as the game entered the final 20 minutes.
Antrim raised their game over the next 14 minutes and reduced the deficit to four points. In this purple patch for the visitors, Peter Healy raced through the Leitrim rearguard to fire home a well-taken goal, while Shivers added two points, with McAleese and McCann (free) getting one each.
A late, late Leitrim flurry in response saw the home side's Mark Plunkett and Beirne (free) whip over a point apiece, while Antrim's Shivers, who was also dismissed for a second yellow offence in this period, pointed prior to seeing his second yellow.
Leitrim: Brendan Flynn; Paddy Maguire, Mark Diffley, Conor Reynolds; Jack Heslin (1-02), David Bruen (0-1), James Rooney; Pearce Dolan (0-01), Donal Wrynn; Cillian McGloin (0-01), Keith Beirne (0-06, 3f); Shane Moran (1-00); Domhnaill Flynn, Evan Sweeney (0-01); Riordan O'Rourke. Subs: Jordan Reynolds (0-01) for McGloin (37); Emlyn Mulligan for O'Rourke (47); Mark Plunkett (0-01) for Heslin (53); Conor Farrell for Flynn (58); Darragh Rooney for Sweeney (67).
Antrim: Michael Byrne; Eoghan McCabe, Peter Healy (1-01), Patrick McCormick; Marc Jordan, Declan Lynch, Dermot McAleese (0-02); Kevin Small, Conor Stewart; Patrick McBride, Ryan Murray, Paddy McAleer; James Gribbin, Pat Shivers (0-04), Odhrán Eastwood. Subs: Barry McCormick for P. McCormick (46); Conor Murray for Gribbin (48); Ruairi McCann 0 – 2 f for McAleer (49).
Referee: Barry Cassidy (Derry).