Celtic missed the chance to go 14 points clear of Rangers and extend their lead at the top of the Scottish Premiership on Saturday when they were held to a 0-0 draw by their Glasgow rivals in the Old Firm game.
Brendan Rodgers' side began the day eight points ahead of second-placed Aberdeen, who play later on Saturday, but they were left to rue a close-range miss from Scott Sinclair in first-half stoppage time that allowed Graeme Murty's visitors to grab a share of the points.
Rangers had their own chance to end a run of seven Old Firm games without a win in the second half when Craig Gordon denied James Tavernier, but returned to Ibrox with a second successive league draw at Parkhead.
James Forrest had Celtic's first clear chance but fired wide, before Rangers goalkeeper Wes Foderingham made a double-save to deny Sinclair from close range.
Sinclair had an even better chance to open the scoring in the second minute of added time before the break, when Stuart Armstrong's cross from the right found him at the far post but the English attacker could only guide the ball inches wide of the target.
Most of the first-half action had been at the Rangers end, but the visitors had their best chance to go ahead soon after the restart when a counter-attack saw Daniel Candeias crossing from the right. Tavernier connected with a hooked volley that was on target, only for Gordon to deny him with a fingertip save.
Rodgers replaced Moussa Dembele with Leigh Griffiths on the hour mark as he looked for the breakthrough, but it was Rangers who were coming more into the match and soon afterward. Tavernier made a great run down the right and crossed for Alfredo Morelos, whose close-range header was diverted wide by Gordon with an outstretched leg.
Sinclair was substituted for Olivier Ntcham, but again it was Rangers who looked more like scoring via another Morelos header from a Tavernier cross, this time glancing wide of the target.
However, neither side could find a winner in the closing stages, with Celtic extending their unbeaten run in Old Firm games to eight matches.