Rangers swept Dundee United away with a seven-goal salvo that set up a meeting with Motherwell in the CIS Insurance Cup final.

Nacho Novo and substitute Steven Thompson both struck twice, with Dado Prso, Thomas Buffel and Fernando Ricksen supplying the other goals.

United had actually been the better side for a portion of the second half and had Rangers under pressure after Jason Scotland had made it 2-1.

But Ian McCall's men imploded after Buffel made it 3-1 and a rout ensued.

Rangers dominated the first 45 minutes and could have reached the five-goal mark by the break.

The opener was the best of them all with Novo rounding goalkeeper Nick Colgan to net in the seventh minute.

The move had been started by a throw from Rangers goalkeeper Ronald Waterreus, the Holland international who was recruited from the Manchester City bench on Monday and replaced the cup-tied Allan McGregor.

It involved Gregory Vignal, Alex Rae, Maurice Ross and Prso before Buffel sent Novo sprinting away with a superb through-ball.

United had no answer to the ex-Dundee man's pace but also knew that Prso's 17th-minute header should have been kept out.

Marvin Andrews fired a free-kick into the box but the Croat was some 16 yards out when he beat Colgan, who could not scurry across his line in time to stop the ball going in at the far post.

United's best moment up to then had been a snap header over the bar by Stevie Crawford following good work down the left by Barry Robson.

But their defending was shocking and the rest of the half featured numerous let-offs.

Novo scuffed a shot wide and Prso failed to beat Colgan with a lob after both had been given clear sights of goal. Novo later did the same as Prso and twice the goalkeeper was required to make goal-line grabs when Rangers defender Sotirios Kyrgiakos won back post headers despite being outnumbered.

United's nervousness was also evident when Mark Kerr was booked for a late challenge on Ricksen in the 13th minute and Alan Archibald for a needless and transparent handball 25 minutes later.

Fortune did favour them in the 40th minute when Colgan saved Novo's penalty, guessing correctly to dive low to his right and justice did seem to have been done as Paul Ritchie's tug of war with Prso in the box had not seemed too serious.

Changes had to be made and McCall duly made them at the break, with ex-Ranger Derek McInnes and Archibald replaced by Scotland and Stuart Duff in a switch from 4-4-2 to 3-5-2.

Scotland's introduction paid off within five minutes when he capitalised on a clumsy Andrews error that presented him with the ball in the box. He took the ball on calmly and slotted under Waterreus' body.

The whole United team were instantly transformed by the breakthrough and began to pummel Rangers.

Jim McIntyre could not believe his luck when his drive beat Waterreus all ends up only to hit one post, bounce across goal on to the other and then into the goalkeeper's arms.

Crawford then had a penalty shout turned down when his close-range effort hit an outstretched Andrews arm and Kerr forced Waterreus into an acrobatic tip around the post.

Rangers had offered little in return during this spell but once again found the answer to their problems in Novo's pace.

The Spaniard broke free down the right and set Buffel up for an easy chance in front of goal, with the Belgium international converting from six yards out despite Lee Mair's challenge to record his first goal since his £2.3million switch from Feyenoord.

Rangers could relax at last and with 69 minutes gone, on came Barry Ferguson for Rae to begin the party.

It was the Scotland skipper's 27th birthday as well but he had celebrated on Monday by being granted the transfer from Blackburn he had craved. His arrival was greeted with rapture from the Rangers fans, who soon had much more to cheer about.

Prso was also handed a rest, with Thompson taking over, and with a quarter of an hour to go United sent on ex-Rangers striker Billy Dodds for defender Mair.

Ricksen made it 4-1 in the 78th minute with a sweetly-stuck free-kick that had been won by Thompson.

The substitute added the fifth not long afterwards with a well-struck effort from a Maurice Ross cross and Novo made it 6-1 in the 85th minute with his second.

A quickly-taken Ferguson free-kick had caught the United back line in suspended animation and Novo fired past the stranded Colgan at the earliest opportunity.

There was still time for a seventh and that was netted by ex-Arab Thompson, who poked past Colgan after the goalkeeper had spilled a fierce Ferguson drive.