Kelechi Iheanacho's first goal in six months saw Celtic cut the gap on William Hill Premiership leaders Hearts to three points as they ended their troubles in Dundee with a 2-1 win at Dens Park.
Iheanacho out-muscled Ryan Astley to control fellow substitute Marcelo Saracchi's cross and fire home the winner from six yards.
The 82nd-minute goal ensured the third-placed champions took advantage of Hearts dropping two points at bottom club Livingston earlier in the day.
Celtic had lost in all three previous trips to Dundee this season and looked like they might slip up again when Simon Murray equalised from a VAR-assisted penalty in the 57th minute.
Steven McLean ultimately pointed to the spot after Astley hit a bouncing ball off the outstretched arm of Colby Donovan.
Dundee had rarely threatened before then and had fallen behind when Yang Hyun-jun got the final touch in an eighth-minute attack.
Celtic missed a series of chances before the leveller but Iheanacho's long-awaited goal was soon followed by a red card for Astley as the visitors made the three-way title fight as tight as it has been all season.
Hearts reclaimed their status as William Hill Premiership leaders but missed the chance to restore their three-point cushion.
The Jambos had been knocked off the top for the first time since September after Rangers edged ahead of them on goal difference by defeating Dundee United on Saturday.
Although they ended the weekend a point clear at the summit with six games to play, there was a huge sense of frustration among the 7,000 travelling supporters at Almondvale after the Edinburgh side dropped points for the fourth away game in succession.
Goals from Hearts strikers Lawrence Shankland and Claudio Braga had overturned Stevie May's early opener, only for the Lions to equalise through Lewis Smith.
And Hearts finished the game with 10 men as Marc Leonard saw red in added time.
