Lorenzo Amoruso wrapped up the Treble for Rangers on a sultry day in Glasgow more in keeping with his native southern Italy, as his header kept the holders' firm grip on the Scottish Cup and deflated defiantDundee.

It may prove to be the epitaph on Amoruso's Ibrox career. The towering defender is set to join Blackburn Rovers, though Alex McLeish - who has annexed all the honours in his first full season as Rangers' manager - may yet persuade him to change his mind.

"There's nothing cut and dried with Lorenzo yet, we have to wait and see," said McLeish, who also paid tribute to Dundee's energy in a pulsating final. "My lads were out on their feet at the end, and Dundee were very dangerous."

Dundee's manager, Jim Duffy, knew he had been the victim of the fine line between success and frustration. "The effort my players put in deserved more, I am very disappointed at the soft free-kick that led to Amoruso's goal."

The last time Dundee contested a Scottish Cup final was in 1964, which was so long ago that their star striker that day, the celebrated Alan Gilzean, still had hair. Coincidentally, the team that beat them that day were Rangers.

Though McLeish's side stood on the brink of a domestic clean sweep, the 20,000 fans who came down from Tayside did so with optimism. They had seen their heroes shake Rangers just a month earlier, when the champions required a late penalty to prevent Fabian Caballero's sumptuous goals inflicting defeat.

That belief would have soared to the heavens had Barry Smith not suffered cruel misfortune after just three minutes, conjuring up a right- foot volley from outside the area that cannoned off the post with the goalkeeper, Stefan Klos, beaten. Six minutes later, the pace of Steve Lovell carved Rangers apart as Mark Burchill threaded a pass to his partner's feet. It required Klos to dash off his line and block Lovell's shot with his body.

Rangers were shorn of one key element, with Mikel Arteta succumbing to injury. Dundee seized on the Spanish midfielder's absence and dominated that area in the opening period. But this flowing encounter was finely poised, with counter-attacks occurring from both ends, and Rangers did induce one moment of panic when Michael Mols rose to meet a free-kick from Neil McCann and thumped the bar with his header.

However, it is Ronald de Boer who required most vigilance. The Dutch international executed a sublime turn after gathering a pass from Barry Ferguson and slipped away from his marker, Lee Mair, but Julian Speroni, was equal to De Boer's angled shot and got a touch to take it wide. Then Burchill saw his netbound shot blocked by Arthur Numan as Dundee underlined their unquenchable ambition before half-time.

Few concessions were made to the fierce heat, and the second half saw both sides continue their quest for the opening goal. Dundee opted to use the pace of Lov-ell, and the striker opened up Rangers twice before the hour.

On the first occasion, Craig Moore just snuffed out the danger, and on the second - after Lovell had left Amoruso and Robert Malcolm trailing in his wake at the half-way line - Caballero chose the wrong option after he was set up.

Dundee's pressure was cranked up another notch when they earned two free-kicks, but neither delivered. Rangers punished that profligacy and provided a lesson in finishing when they broke the deadlock in the 66th minute from a free-kick of their own. Zurab Khizanishvili foolishly conceded a foul out near the corner flag, allowing McCann to flight a perfect ball for Amoruso - who had eluded Khizanishvili - to attack and thump a header into the roof of the net.

Rangers sensed the trophy was theirs, but their tired legs offered Dundee several chances, with Nacho Novo squandering one and his fellow substitute, Garry Brady, forcing Klos to smother his shot as the tension rose in the dying minutes.

The final whistle brought Rangers relief and joy at completing their haul of trophies, and Amoruso said: "I don't know if I will go or stay, but if I do go then it's the best way to say thanks very much."

Dundee 0 Rangers 1
Amoruso 66

Half-time: 0-0 Attendance: 47,136