Our look at five unheralded victories over our greatest rivals concludes - for now - with this must-win game in 2003.
The 2002-03 season has become so indelibly linked with our road to Seville that the title race - which was decided on goal difference - has mostly been forgotten about. However, Celtic put up a terrific fight to retain our title whilst faced with at times what seemed like insurmountable problems.
For example, take this game, which we went into six points behind Rangers - albeit with a game in hand - but without our talisman Henrik Larsson, who was out with a broken jaw, but, as so often happened in the Martin O'Neill era, the Bhoys turned adversary into opportunity and ground out a vital victory.
The best chance of the first half fell to John Hartson, who took a fresh air swipe at the ball in the six yard box with the goal gaping. The same player missed a great chance early in the second-half, as he put free header wide of the post. Thankfully, it was third time lucky for Big John in the 57th minute, as he received the ball from a Chris Sutton knockdown, took a touch and smashed an unstoppable volley into the next. One of his best goals for Celtic.
Neil Lennon of all people almost got our second ten minutes later but his shot flew just wide of the goal. The only real chance for Rangers arrived with two minutes left, but Rab Douglas pulled off a great save from a Lorenzo Amoruso free-kick.
The final whistle brought scenes of wild celebrations as Celtic propelled ourselves back into the title race with yet another one of those against all the odds, never say victories which we've been doing for the last 130 years...and here's to many more of them!
Celtic 1 (Hartson 57') Rangers 0