Dundee United striker Jon Daly crashed in a last-minute goal to hold league leaders Celtic to a draw at Tannadice.
Shunsuke Nakamura curled in a delightful free-kick on 48 minutes to put the visitors ahead.
And United's hopes of a comeback appeared to vanish when captain Barry Robson was shown a late red card for a violent clash with Lee Naylor.
But the home side continued to press and Daly blasted in a fine strike with almost the last kick of the ball.
Runaway leaders Celtic have now picked up just one point from their last three league matches.
Dundee United made three changes from the side that beat Hearts 4-0 in their last outing; with Collin Samuel, Morgaro Gomis and Stuart Duff replacing the suspended trio of Noel Hunt, David Robertson and Christian Kalvenes.
MY SPORT: DEBATE
Duff was a late call up after teenager Keith Watson was hurt during the pre-match warm-up.
Jan Vennegoor of Hesselink returned to lead the Celtic attack, while Aiden McGeady, Darren O'Dea and Gary Caldwell were also given starts.
Caldwell, playing for the first time since sustaining a knee injury in November, was deployed at right-back and was eager to get forward in a lively opening period.
United midfielder Mark Kerr's hit a shot narrowly wide from 25 yards, while David McCracken got a vital touch to deny Vennegoor of Hesselink a close range header.
Home skipper Robson tested Artur Boruc with a low free-kick, before the Polish goalkeeper carelessly spilled another stinging drive from Robson but there were no takers for the loose ball.
Celtic were moving the ball around well despite the badly rutted pitch but United posed a more direct threat.
Boruc was given another scare on the half hour when a curling delivery from Steven Robb eluded him and crashed off the crossbar.
Celtic responded with a powerful strike from McGeady that was pushed away by the diving Derek Stillie.
And, with the interval looming, United striker Collin Samuel dragged a strike wide from 16 yards with the Celtic defence backing off.
The second half was three minutes old when Celtic won a free-kick 25 yards from goal and Nakamura stepped up to curl it over the wall and into the opposite corner from the static Stillie.
Robson drilled another strike inches wide and hit the side-netting with a free-kick after Jon Daly had an effort cancelled for offside.
Vennegoor of Hesselink did well to break into the United penalty box and send the ball across goal but substitute Maciej Zurawski was slow to react.
Robson had been the driving force for United but he was sent off after clashing with Naylor in the closing stages.
However, the home side were rewarded for their enterprising play when Daly found the net with a great shot on the turn from 18 yards.
Dundee United: Stillie, Dillon, Wilkie, McCracken, Duff, Samuel (Easton 87), Gomis (Goodwillie 76), Kerr, Robson, Robb (Cameron 80), Daly. Subs Not Used: McLean, Gardiner, McCord, Andreoni.
Sent Off: Robson (89).
Booked: Wilkie.
Goal: Daly 90.
Celtic: Boruc, Caldwell, Pressley, O'Dea, Naylor, McGeady, Lennon, Hartley, Nakamura, Vennegoor of Hesselink, Beattie (Zurawski 60). Subs Not Used: Brown, Riordan, Gravesen, Perrier Doumbe, Sheridan, Kennedy.
Booked: Beattie, Vennegoor of Hesselink, Naylor.
Goal: Nakamura 48.
Att: 11,363
Ref: I Brines