Celtic capitalised on Hearts' earlier slip-up to move within three points of the Scottish Premiership leaders as Kelechi Iheanacho slammed in a dramatic late winner at Dundee.

Yang Hyun-Jun opened the scoring for Martin O'Neill's side inside eight minutes by getting a slight touch on Benjamin Nygren's close-range shot and they should have been further in front before half-time, with striker Tomas Cvancara missing several gilt-edged chances.

And their wastefulness came back to bite them after the break.

Video assistant referee (VAR) Matthew MacDermid spotted a handball by full-back Colby Donovan and referee Steven McLean pointed to the spot after going to the pitchside monitor.

Home captain Simon Murray calmly converted to level the scores and Celtic took their time to wrestle back their momentum.

However, with time running out, substitute Iheanacho lashed a left-footed shot past stricken home goalkeeper Jon McCracken to secure all three points.

Dundee were then reduced to 10 men as centre-back Ryan Astley was dismissed for taking out Yang.

After Hearts drew at Livingston earlier on Sunday, Celtic narrow the gap to the Tynecastle club, while they trail Rangers in second by two points.

Dundee remain five points clear of Kilmarnock in the relegation play-off spot.

For all their shortcomings this season, Celtic have never been out of contention in the Premiership and despite an imperfect performance at Dens, they found a way to win.

They had lost on their three previous visits to the city this season, but started on the front foot and deservedly hit the front.

After McCracken spilled Cvancara's initial effort, a combination of Yang and Nygren bundled in.

From there, it was wave after wave of Celtic attack, but as has been the case for the majority of this season, their starting striker failed to deliver.

Cvancara shanked high and wide from about 25 yards out and then hit the post when good work from Daizen Maeda put the Czech Republic international through on goal.

He failed to capitalise on another golden chance early in the second half and was replaced by Iheanacho just before the hour mark.

His profligacy appeared to be costly when Murray swept home from the penalty spot.

Celtic have now conceded in their past eight league matches, their longest run without a clean sheet in 20 years.

And yet, with time running out, Marcelo Saracchi swung in a dangerous cross from the left and Iheanacho took advantage after Astley failed to clear.

O'Neill spoke before kick-off about how still being in contention at full-time would constitute success. His team delivered, just.

Dundee have grown as the season has progressed and after a difficult first half, they posed Celtic plenty of problems in the second.

Pressley praised how his players approached the game and he was right to.

They took risks in possession and were not sitting in playing risk-averse football.

They still have work to do to avoid relegation, but on this showing, they will be just fine.

Dundee head coach Steven Pressley: "I don't think we started the game in the fashion we hoped. That was credit to Celtic.

"We settled into it and especially in the second half we played particularly well. We didn't come out to sit in, we wanted to impose ourselves on the game and that takes bravery.

"To stay in this league, you're going to have to endure difficult games and difficult periods.

"The last six games are going to challenge us greatly. We need to attack them and keep showing the bravery we showed today."

Celtic interim manager Martin O'Neill: "I thought we played brilliantly in the first half, got our goal and should have got two, three or four. You always felt it would come back to haunt you and it did.

"They got their tails up after the penalty and it was really hard work.

"But we created another chance or two and Iheanacho puts one in the net.

"I think overall we deserved to win the game but it was always going to be tight. And we made it really tight."

Dundee are away to Kilmarnock on Saturday (15:00), while Celtic host St Mirren at the same time.