De Boer scored twice and really should have had a hat-trick if some of his team mates had not been greedy towards the end while Tony Vidmar and Shota Arveladze also scored in an amazing night for McLeish.
It was the type of performance which can bond a team and the new boss must be hoping that this is the case as he heads into Saturday’s Cup clash with former club Hibs.
It had been raining all day in Fife and Alex McLeish must have felt a cloud had positioned itself immediately above his head in the first half as Rangers fell two goals behind.
The lead possibly flattered Dunfermline a little as both goals – scored by stand-in skipper Scott Thomson – were opportunistic but Rangers were desperately poor in the first 45 minutes.
McLeish had gone with the strongest 11 available, but the Ibrox men, who had not lost a goal in their previous six matches, seemed very one-paced and any time the ball reached the strikers Andrius Skerla and Justin Skinner proved to be a formidable barrier.
The Rangers manager expected more from his frontmen, but it just did not happen for Arveladze and Caniggia. This point was proved in 23 minutes when Caniggia just needed a touch on Arveladze’s deflected shot but missed the ball.
By then, though, Rangers were one down, losing a goal after 17 minutes following Dunfermline’s first corner and you can bet that McLeish was furious at the simplicity of the concession.
Sean Kilgannon, on loan from Middlesbrough, swung the ball over from the right and Thomson was unmarked as he directed a header past Stefan Klos from eight yards out.
Rangers were rocked and although they tried to pass their way back into the game, Dunfermline packed their backline so tightly, there seemed no way through.
Referee Alan Freeland did not help in 30 minutes when he allowed a wild challenge by Skinner on Caniggia to go unpunished as he tried to allow the advantage when a freekick in the penaly box arc would have been infinitely more advantageous to Rangers.
And almost a minute later there was further complaint from the Rangers fans when Ricksen brought down Kilgannon and the loan star almost knocked the Dutchman over in retaliation.
Ronald de Boer complained and the end result was a yellow card for each player and a freekick for The Pars wide on the left side of Rangers’ box. It turned out to be another black cloud moment for McLeish.
Former Ranger Barry Nicholson whipped the ball over and Thomson was unmarked again as he powered a header at the back post which Klos could not stop from going into the net.
McLeish must have thought there and then that it was going to be a black night but he knew his team was under-achieving by some distance and some tasty words of encouragement at half-time did the trick!
Within two minutes of the restart, Rangers were back in the game and by the 62nd minute they were on their way to a victory which looked quite unlikely at half-time.
Arveladze won a corner on the right and then worked a short one with Peter Lovenkrands before the Dane swung the ball over. Craig Moore headed it down and fellow Aussie Tony Vidmar forced the ball home.
There was a new drive and purpose to Rangers and seven minutes later they were level and it was as a result of a blunder by Pars keeper Scott Thomson.
Lovenkrands found some space on the left and whipped over a good cross which Thomson seemed to have but he dropped it at the feet of de Boer who gladly accepted the gift and clipped a left foot shot into the net.
Dunfermline were shell-shocked and by 62 minutes they were a beaten side as Rangers conjured up a fabulous third goal to set up a remarkable win.
For the third running game Amoruso had a huge influence when he produced a delightful pass over the top of The Pars defence which was pefect for de Boer who had timed his run to perfection.
The Dutchman took his time and then lifted the ball past Thomson to the utter joy of the Rangers fans behind the goal.
The Ibrox men were rampant now with de Boer and Lovenkrands ripping them apart at times with their craft and pace.
Indeed it was the young Dane’s skill which led to the fourth goal in 80 minutes. Lovenkrands skipped past Thomson and was then hauled down in the box by Stewart Pertrie who had only just come on.
Arveladze was given the responsibility with the spotkick and made the game absolutely safe with a textbook penalty, sending the keeper the wrong way.
Star performer de Boer might have had a hat-trick, but his back heel got stuck in the mud while Arveladze and Lovenkrands also had chances but in the end Rangers settled for four.
The second half comeback might just be the making of Rangers under the new manager.
DUNFERMLINE: Scott Y Thomson; Skinner (Nicholls 75), Skerla, Scott M Thomson; MacPherson, Nicholson, Mason, Panopoulos (Petrie 59), Kilgannon (Dair 59); Crawford, Bullen. Subs not used – Harrower, McLeish.
Bookings: Kilgannon (31) Petrie (60) Mason (76)
RANGERS: Klos; Ricksen, Moore, Amoruso, Vidmar; De Boer, Konterman, Ferguson; Caniggia (McCann 70), Arveladze, Lovenkrands. Subs not used – Christiansen, Dodds, Ross, Hughes.
Bookings: Ricksen (31), de Boer (31)
Ref: Alan Freeland.
Att: 8,795
Man of the match: Ronald de Boer
Moment of the match: Amoruso’s pass for de Boer’s first goal.