Match ends, Dundee United 0, Celtic 1.
Striker Albian Ajeti's first Celtic goal will "do his confidence the world of good," says manager Neil Lennon.
Ajeti, on as a substitute for his league debut, hit the winner seven minutes from time at Dundee United to spare the champions from a second consecutive Scottish Premiership draw.
The 23-year-old Swiss international recently arrived in a £4.5m deal after an unhappy year at West Ham United.
"He's had an early impact already and that's great for us," said Lennon.
"He's not match fit, he's not had a lot of football in the last 12 months. But he did great to keep the ball alive for the goal and his link-up play was good as well. It's brilliant for him."
United had impressively subdued Lennon's side, who were playing their first league fixture in 13 days after having two games postponed for defender Boli Bolingoli's quarantine transgression.
But Celtic's pressure finally told as they found a way past inspired goalkeeper Benjamin Siegrist.
United - with four players aged 22 or under - energetically harassed the visitors, who hit the post through Odsonne Edouard in the first half.
Siegrist was kept increasingly busy, with the pick of his saves a leap to turn away a Christie effort bound for the top corner.
Celtic kept pushing and substitute James Forrest fired inches over, Callum McGregor drilled wide and Edouard grazed the bar with a free-kick.
Their perseverance finally paid off when Siegrist could only palm a Christie drive into the air and Ajeti collected the rebound to fire past three despairing United players on the goal line.
Man of the match - Benjamin Siegrist
What did we learn?
Celtic looked better suited to a front two. Ajeti's introduction off the bench gave sole striker Edouard a partner up front and led to the crucial breakthrough. Ajeti didn't come cheap at £4.5m from West Ham United, but the 23-year-old's contribution in this tight Tannadice tussle could prove priceless months down the line.
United, meanwhile, already look an accomplished Premiership side just five games in. Micky Mellon has them well drilled and disciplined, with a blend of youth and experience that should keep them clear of any relegation worries.
What did they say?
Dundee Utd manager Micky Mellon: "I'm pleased with my players and very frustrated at not getting something from the game. It gives us something to work from. We have a lot of talented young players with great desire."
Celtic manager Neil Lennon: "The players' attitude was tremendous, they didn't get frustrated and kept going. We got the goal we thoroughly deserved - we were outstanding at times. I think 1-0 flattered Dundee United."
Celtic switch focus to Europe on Wednesday with a Champions League second-round qualifier at home to Ferencvaros, before returning to Premiership business at home to Motherwell next Saturday.
United are also in Saturday action as they look to bounce back from a second successive home defeat when they travel to Kilmarnock.
- 30NeilsonSubstituted forFreemanat 60'minutesBooked at 90mins
- 18ButcherBooked at 80mins
- 20BoltonSubstituted forMcMullanat 74'minutes
- 15ChalmersSubstituted forSporleat 65'minutes
- 10ClarkSubstituted forAppéréat 74'minutes
- 3TaylorSubstituted forAjetiat 73'minutes
- 8BrownBooked at 83mins
- 42McGregorBooked at 26mins
- 21NtchamSubstituted forAjerat 74'minutes
- 27ElyounoussiSubstituted forForrestat 62'minutes
- 22EdouardSubstituted forKlimalaat 86'minutes
- Andrew Dallas
- Shots on Target
Second Half ends, Dundee United 0, Celtic 1.
Kieran Freeman (Dundee United) is shown the yellow card for a bad foul.
Patryk Klimala (Celtic) wins a free kick in the attacking half.
Foul by Kieran Freeman (Dundee United).
Attempt saved. James Forrest (Celtic) right footed shot from the centre of the box is saved in the centre of the goal. Assisted by Jeremie Frimpong with a cross.
Corner, Dundee United. Conceded by James Forrest.
Scott Brown (Celtic) wins a free kick in the defensive half.
Foul by Calum Butcher (Dundee United).
Kristoffer Ajer (Celtic) wins a free kick in the defensive half.
Foul by Louis Appéré (Dundee United).
Substitution, Celtic. Patryk Klimala replaces Odsonne Edouard.
Ryan Christie (Celtic) wins a free kick on the right wing.
Foul by Jamie Robson (Dundee United).
Scott Brown (Celtic) is shown the yellow card.
Goal! Dundee United 0, Celtic 1. Albian Ajeti (Celtic) right footed shot from the centre of the box to the centre of the goal.
Attempt saved. Ryan Christie (Celtic) left footed shot from outside the box is saved in the top left corner. Assisted by Scott Brown.
Odsonne Edouard (Celtic) hits the bar with a right footed shot from outside the box from a direct free kick.
Calum Butcher (Dundee United) is shown the yellow card for a bad foul.
Odsonne Edouard (Celtic) wins a free kick in the attacking half.