Rangers goalkeeper Allan McGregor produced a superb penalty save to give the reigning champions a draw with Celtic and keep the title race alive.
Steven Davis was ruled to have fouled Anthony Stokes, but McGregor pushed Georgios Samaras's late spot-kick wide.
The sides kept a lid on a potentially feisty derby during a lively first half that nevertheless produced few chances.
Rangers' Kyle Lafferty flashed a header wide after the break, while McGregor also thwarted Daniel Majstorovic.
And the Scotland goalkeeper's penalty save prevented Celtic securing a victory that would have sent them to the top of the Scottish Premier League by two points with a game in hand.
The build-up to the game had been overshadowed by parcel bombs sent to Celtic manager Neil Lennon and two other prominent fans.
Walter Smith went into his final Old Firm game as Rangers manager hoping to even up the scores with Celtic having won three and lost two of the previous Glasgow derbies this season.
But an even game that ended both sides' five-match winning run concluded with Lennon the happier of the managers as his side will now win the title if they win all five of their remaining fixtures.
Smith had returned to the line-up that overcame Celtic in the Co-operative Insurance Cup final, with the exception of McGregor being preferred to Neil Alexander in goal.
That meant Gregg Wylde coming in for Kyle Hutton, but the Celtic midfield provided the bigger pre-match surprise.
Joe Ledley, who was expected to miss out through injury, and Ki Sung-Yueng were preferred to Kris Commons, who scored two goals in midweek against Kilmarnock, and James Forrest.
Samaras, who had caused Rangers problems in earlier encounters, was chosen ahead of Stokes up front.
However, it was Rangers on the front foot in the early stages as Ibrox shuddered in a cauldron of noise produced by both sets of fans, with Wylde and Davis delivering dangerous crosses into a Celtic box nervously patrolled by punch-happy goalkeeper Fraser Forster.
Ledley had claims for a penalty correctly waved away by referee Craig Thomson after running into Steven Whittaker.
Rangers, though, were first to threaten and a Maurice Edu shot deflected a foot wide off Charlie Mulgrew.
The first flashpoint came after 22 minutes, with a spot of mutual shoving from Samaras and David Weir, but a yellow card each calmed what can so often be volatile proceedings.
Scott Brown had Celtic's first effort on goal with a low drive from 20 yards that curled a few yards wide after Mark Wilson dispossessed Davis.
Steven Naismith wildly sliced wide from 12 yards at the other end when found in the clear at the far post by a long Sasa Papac diagonal ball as the first half deteriorated into a midfield war of attrition.
Weir had the first chance of the second half but headed over from 14 yards after climbing well to meet a Davis corner, while Daniel Majstorovic did well to deflect a Naismith drive wide.
Kyle Lafferty squandered a great chance to give Rangers the lead when he beat Mulgrew to a Wylde cross to the front post, but the forward flashed his header just wide.
Celtic responded and a 22-yard Beram Kayal drive flew inches wide then McGregor produced a breathtaking finger-tip save to deflect a close-range Majstorovic header for a corner.
Lafferty flashed a free-kick wide of the far post, while Naismith fired across the face of goal and narrowly past from the edge of the box.
McGregor did well to tip an Emilio Izaguirre chip over the crossbar after the full-back had stepped inside Whittaker.
It looked like Celtic would secure the victory when Thomson pointed to the spot after 83 minutes.
The decision looked harsh, with Davis at most being guilty of obstruction, but McGregor was on hand to save the day for a Rangers side who remain top by a point.
Stokes went down again in the box in the dying seconds under a John Fleck challenge, but this time Thomson booked the substitute for diving.