Dundeeās March misery continued at Dens as they slumped to their third successive defeat this month, albeit by the narrowest of margins to champions elect Celtic.
The Dark Blues were certainly not lacking in honest endeavour but overall when it mattered, the Hoops just had the edge in quality.
The Glasgow giants opened the scoring in first-half stoppage time through Jozo Simunovic and then made it two courtesy of Stuart Armstrong shortly after the restart. The home fans were given hope when sub Faissal El Bakhtaoui reduced the deficit with an outstanding goal but Celtic left with all three points to stand on the verge of another title.
Dark Blues boss Paul Hartley reacted to last weekās desperately disappointing defeat at St Johnstone by drafting in Tom Hateley and Kevin Gomis for Craig Wighton and Kosta Gadzhalov.
Celtic manager Brendan Rodgers made two changes from the team that drew with Rangers at Parkhead last week with Erik Sviatchenko and Nir Bitton dropping to the bench to be replaced by Simunovic and Callum McGregor who was making his 100th appearance for the Glasgow side.
Aberdeenās victory over Hearts on Saturday meant that the Hoops could not win the league at Dens with the champagne being put on ice for at least another week.
However, there was still a large Celtic support inside the ground with both sets of fans observing a minuteās silence prior to kick-off for former Lisbon Lion and Dark Bluesā League Cup-winning skipper Tommy Gemmell who passed away recently.
Celtic clicked into gear early, dominating possession but struggled to create clear-cut chances. Armstrong did have a pop with a long-range free-kick in the 13th minute but his effort flew well over Scott Bainās bar.
Shortly after, the Hoops midfielder swung in a corner from the left with Moussa Dembele winning a header but he put his effort wide when he should have hit the target.
As the first quarter passed, the home side were still struggling to make any impact in an attacking sense.
However, Hartley would have been pleased with his teamās defensive work ethic that ensured Bain did not have a lot to do in the Dundee goal.
The keeper did have to look lively in the 29th minute as the ball was played through towards his goal but Bain won the race with Scott Sinclair to snuff out the danger.
Dundee did finally force successive corners in the 35th minute but Hateleyās efforts from either side were comfortably dealt with by the Celtic defence.
Soon after, Dark Blues full-back Cammy Kerr made a crucial intervention as Sinclair looked odds-on to score with a close-range header.
It looked like Dundee would go in at the break level especially when Paul McGowan superbly cleared a Dedryck Boyata header off his own line.
But then in the first minute of stoppage time, it was heartbreak for the Dark Blues when James Forrest dinked a cross from the right towards Simunovic who scissor-kicked the ball from 12 yards with his effort taking a deflection off Gomis before nestling just inside Bainās left-hand post. It was an absolute hammer blow for the hard-working Dark Blues on the stroke of half-time.
The home side had a chance three minutes into the second half when Gomis was fouled 22 yards from the Celtic goal. Kevin Holt stepped up to take the free-kick but his strike was easily gathered by Craig Gordon.
However, Celtic increased their lead in the 52nd minute when Forrest was again the provider sending a great cross from the right with former Dundee United star Armstrong directing a powerful header past Bain from six yards.
The Dark Blues then squandered a superb opportunity to pull a goal back 10 minutes later when Paul McGowan teed up Marcus Haber on the edge of the Celtic penalty area but the big Canadian striker shot wide with the goal at his mercy.
Dundee did though dig out a lifeline with a goal of the highest quality in the 76th minute. El Bakhtaoui skinned Boyata and then raced through on the Celtic goal before unleashing an unstoppable shot from 22 yards high past Gordon.
Haber then had another chance when he latched on to a Cammy Kerr delivery but his header was well wide of the mark.
Dundee went looking for a grandstand finish but it was not to be with the Celtic travelling support gleefully celebrating at the final whistle.
Attendance ā 8,968.
Dundee ā Bain, Holt, Vincent (Wighton, 59), OāDea, Hateley (Ross, 68), OāHara, McGowan, Haber, Ojamaa (El Bakhtaoui, 74), Kerr, Gomis.
Subs not used ā Mitchell, Williams, Klok, Gadzhalov.
Celtic ā Gordon, Simunovic, Brown, Dembele, Sinclair (Sviatchenko, 83), Armstrong, Boyata, Lustig, McGregor (Kouassi, 68), Forrest (Roberts, 72), Tierney.
Subs not used ā Bailly, Bitton, Griffiths, Gamboa.
Referee ā Willie Collum.