Rangers now trail Celtic by seven points in the title race and to make matters worse they had Lorenzo Amoruso sent off and both Claudio Reyna and Barry Ferguson were helped off with what looked quite serious injuries.
Yes, the Light Blues gave it their all and they played some tremendous football at times but they could not make it count. Celtic were reminiscent of Walter Smith’s Rangers at times as they soaked up the pressure and then struck twice – the second coming in injury time through Alan Thompson.
It will now take a huge effort from Advocaat and his players to turn things around, although he does have the respite of no further league action for a fortnight to regroup his forces.
The Rangers boss took the partial gamble of bringing back Michael Mols and Claudio Reyna, sensing that he needed to trickery of Mols coupled with the power and precision of Reyna to unlock Celtic.
His decision was entirely justified, even although Reyna later came off, as his attacking side completely dominated the first half with some slick inter-passing and excellent movement.
However, the travesty was that Rangers found themselves a goal behind at the interval and even worse it was as a result of a personal blunder by the normally ultra efficient Stefan Klos.
The German keeper, however, was to redeem himself with a sensational penalty save in 65 minutes which kept Rangers alive and another great block from Agathe which was similarly vital, but it was still a howler by his standards.
Celtic had scarcely had a kick in the game when they won a soft freekick in a left central area about 25 yards out when Kenny Clark decided Craig Moore’s challenge on Chris Sutton was unfair.
Klos lined up his wall well enough, Henrik Larsson touched the ball to Stilian Petrov and he hammered a right foot shot which Klos seemed to have covered but as he went to block it, the ball spun off his body and flew into the roof of the net.
He lay on the turf in horror when he had learned what he had done and Dick Advocaat must have wondered there and then if it simply was not going to be his day.
Rangers, inspired by the magnificent Lorenzo Amoruso, tried to roar back immediately when Numan played a terrific 1-2 with de Boer and picked out Flo at the near post but the big striker’s stabbed shot flew just wide.
The Light Blues probed and prompted all over the field, making Celtic look decidedly second best, but they could not find the openings their domination deserved.
De Boer was at his exqusite best, with much of the play centring around the Dutchman while Reyna was also immense in midfield but the bottom line was Rangers were behind.
Numan played Reyna in with a superb cross field ball in 28 mintues but Mjallby brilliantly cut out the American’s cross which was destined for Flo.
Then in 34 minute Numan’s cross from the left travelled all the way to Ricksen but he did not get enough power in his header and Douglas saved easily.
Two minutes later Numan squared the ball to the same player and Reyna drilled a right foot shot which was blocked by Bobo Balde when it looked as though it would cause Douglas some trouble.
It took until the 39th minute before Celtic had another dangerous moment, such was Rangers’ complete control of the game. Ferguson gave away a foul on Larsson. This time Alan Thompson tried his luck with the freekick and this time Klos was equal to it, clutching the ball safely.
Rangers desperately need a goal and it looked like they had it in 43 minutes. Ricksen hammered a freekick from his own half which got all the way through to Mols on the left side of the box.
The ball seemed to have dropped nicely for a left foot volley but he got under it and the chance was lost as the ball sailed into the Broomloan Stand.
Rangers were unrelenting when the second half started carving three good chances in the first 13 minutes. Crucially, they took none of them.
Konterman was presented with a free header from Reyna’s corner a minute after the break, but he put his effort a foot wide. Then a minute later Mols was only inches away from convering Moore’s cross, but again it slipped past the right hand post.
Then in 58 minutes Ricksen burst down the right away from Thompson, crossed for de Boer who headed the ball into the path of Reyna who slid in at the right hand post but could not divert the ball into the net.
The game, however, exploded in 63 minutes. Moore was slack with a ball forward which allowed Petrov to break and he quickly released Larsson who was in with a clear sight of goal.
Amoruso brought him down and had to go off for a last man challenge and suddenly the match looked all over for Rangers. Lambert, for some reason, got involved in the ensuing arguments and was booked, as was Ricksen.
Finally Larsson spotted the ball and the stadium held its breath. The Swede shaped to hit if left then hammered it to the right but Klos guessed correctly and made a brilliant blocking save.
Reyna, who had injured himself stretching earlier, was replaced by Claudio Caniggia but Rangers were up against it now and entirely susceptible to the counter attack.
They contineed to swarm forward and buzzed around the Celtic box, but seemed unable to find the killer pass as the clock counted down.
Klos was again forced to make a brilliant double save from Didier Agathe in 72 minutes to keep Rangers in it when the Celtic winger seemed destined to close the game out.
Rangers were still in it and Numan tested Douglas with two driven left foot shots but on each occasion he made the save. The Celtic goal was virtually under siege but it just would not happen for Rangers.
Fate conspired against Rangers in the final moments when skipper Barry Ferguson had to go off with a back injury after a challenge by Thompson and to rub salt into Rangers’ wounds Thompson scored a second goal in injury time.
The Geordie midfielder skipped away from three Rangers players on the left side – Ricksen, Moore and Konterman – and then placed a terrific right foot shot beyond Klos to seal a quite miserable day.
Advocaat can quite rightly say that his side was the superior one on another highly tense Old Firm encounter but it was Celtic who left with the three points and that is the key.
RANGERS: Klos; Ricksen, Moore, Amoruso, Numan; Reyna (Caniggia 66), Konterman, Ferguson (Hughes 87); de Boer; Mols (McCann 75), Flo. Subs not used – Christiansen, Ross.
Sent Off: Amoruso (63)
Bookings: Moore (56), Ricksen (63)
CELTIC: Douglas; Balde, Mjallby, Valgaeren; Agathe, Petrov (Moravcik 71), Lennon, Lambert, Thompson; Larsson, Sutton. Subs not used – Kharine, Hartson, Healy, Maloney.
Bookings: Lambert (63), Sutton (78), Balde (90)
Ref: Kenny Clark.
Att: 50,097.
Man of the match: Lorenzo Amoruso, despite his red card.
Moment of the match: There simply can’t be one after this defeat.