David Fernandez came back to haunt his old side with two goals at Parkhead yesterday, but really it was the men currently wearing Celtic's colours who were most to blame for this concession of vital points.
Gordon Strachan's defensive flaws were again exposed as Dundee United came from 3-1 down with just seven minutes left to snatch a draw. Fernandez's wonderful equaliser will have given Hearts, now eight points adrift, a glimmer of hope in the Scottish Premier League title race.
Celtic used this encounter to provide a debut for Mark Wilson, a £500,000 signing from Dundee United a fortnight ago, and the young right-back's eagerness to get forward contributed to John Hartson's opening goal after nine minutes.
Wilson's advance was halted by Barry Wilson's tackle and that allowed Shunsuke Nakamura to whip over a free-kick that was glanced beyond the goalkeeper Derek Stillie by Hartson from six yards. It was the Welshman's third goal in three meetings with United this season.
Stanislav Varga came close with another header from a perfect Nakamura delivery but the visitors had plenty of chances of their own to endorse their patient passing game.
Jim McIntyre looked to have equalised when he met Barry Robson's cross but his downward header was superbly palmed away by the goalkeeper Artur Boruc.
The visitors kept pressing forward and the same partnership dovetailed again just before the half-hour, with McIntyre planting another header that Boruc needed to stop.
So, perhaps it was no surprise that Craig Brewster's team restored parity five minutes before half-time.
Boruc had already missed a Robson corner and when the same player's free-kick caused panic in Celtic's defence, it was the rampant Fernandez who pounced to score with a shot on the turn. The Spaniard, however, sportingly refused to celebrate against his old club.
But United's joy was short-lived. Maciej Zurawksi restored Celtic's lead within three minutes of the re-start as he netted his fourth goal in four games since returning from injury. The Polish international stole in at the back post to meet Shaun Maloney's free-kick and flicked a header neatly beyond Stillie.
That should have been the signal for Celtic to cut loose and with Wilson's runs tearing his former side apart, United clung on. Wilson's vision picked out Petrov in the 63rd minute and his low cross would have been swept in by Hartson but for Stillie's vital touch.
Celtic went further ahead five minutes later when another Wilson overlap caused panic and when the ball was cleared out of the box, Stilian Petrov thrashed a 25-yard shot that took a deflection off Derek McInnes to elude Stillie.
Yet, from that position, Celtic managed to squander their advantage. Lee Miller finished off McIntyre's header from an offside position just four yards out in the 83rd minute but the goal stood and United seized the initiative.
Then McIntyre threaded another pass into the path of Fernandez and he rounded Boruc to silence Parkhead.Reuse content