Connacht led 1-20 to 1-15 with just seven minutes remaining, but Brogan brought his shooting boots to the Longford venue as his late four-point haul proved crucial.

The Dublin star fisted the match-winning score with three minutes to go as Pat Gilroy’s men set up a final showdown with defending champions Ulster.

A goal from Meath’s Joe Sheridan handed Leinster an early 1-2 to 0-2 lead, but Connacht, with Paul and Michael Conroy in impressive form, foraged ahead by half-time.

Wexford’s Adrian Flynn drove forward from centre-field to add his name to the scoresheet, helping Leinster move 1-7 to 0-8 ahead.

But with Mayo’s Michael Conroy landing successive scores, the westerners soon edged ahead.

Indeed, the John Tobin-managed team hit the final four points of the opening period with Leitrim captain Emlyn Mulligan landing two frees, Sligo’s Mark Breheny on target and Paul Conroy hitting his third point of the afternoon.

The competitiveness of the fare increased after the break as Breheny replied to an early string of scores from Leinster’s John Heslin, Brogan and Redmond Barry.

Paddy Keenan of Louth slotted over to bring Leinster level, but Galway sharpshooter Paul Conroy then pounced on a rare error by Stephen Cluxton to score his side’s only goal.

Brogan spared his Dublin team-mate’s blushes though with a strong finish to this entertaining encounter.

He squared things up at 1-20 apiece before his ninth point of the day sealed Leinster’s passage through to next Sunday’s Interpro final at Croke Park (throw-in 3.45pm).

Leinster last tasted Interpro success in 2006 and they will be keen to deny Joe Kernan’s side their second title in-a-row.

Although Connacht were pipped in a dramatic finish, Mark Gottsche will remember the match for a special reason as he became the first ever London player to line out for the westerners in the Interprovincial Football Championship.

LEINSTER: S Cluxton; K Lillis, G Molloy, B Malone; M Quinn, G Brennan, A Flynn (0-3); MD Macauley (0-1), J Heslin (0-2); B O’Connor (0-2), R Barry (0-1), C O’Sullivan; D Dolan, J Sheridan (1-0), B Brogan (0-9, 0-5f).

Subs used: S McCormack (0-2) for Dolan (17 mins), P Keenan (0-1) for Quinn (31), B Kavanagh for Brennan (52), P Flynn for Sheridan (55), J Stafford for O’Connor (60).

CONNACHT: D Clarke; G Cafferkey, F Hanley, J Moore; L Keegan (0-1), N Daly, G O’Donnell; J Gibbons, S O’Shea; M Breheny (0-3, 0-2f), E Mulligan (0-6, 0-4f), M Martin (0-1); J Doherty, P Conroy (1-5, 0-1 ’45'), M Conroy (0-4).

Subs used: M Gottsche for Martin (31 mins), P Brennan for Gottsche (63).

Referee: Derek O’Mahony (Tipperary)