Match ends, Celtic 5, Dundee United 0.
Kris Commons scored twice as Celtic dismantled struggling Dundee United to move four points clear at the top of the Scottish Premiership.
Leigh Griffiths netted his 13th goal of the season from an acute angle before Dedryk Boyata knocked in a header.
Commons smashed home a penalty before the interval and then found the top corner with a great shot.
Scott Brown added to United's misery with a deflected strike in the closing minutes of a one-sided contest.
The comprehensive victory went some way to making up for Celtic's midweek Europa League loss in Molde.
Manager Ronny Deila admitted before kick off that the criticism that had come his way after a miserable return to his native Norway was justified but insisted his side would bounce back.
And the champions did so with ease as visiting keeper Luis Zwick was kept busy throughout.
Those who decided to forgo Sunday lunch for Celtic Park saw a home side that included Jozo Simunovic for just the second time this season.
The Croatian defender would have precious little to do though because from the first whistle United, who are five points adrift at the bottom, assumed defensive positions and rarely broke free.
Former United pair Gary MacKay-Steven and Stuart Armstrong were prominent as the hosts started with an impressive tempo.
And the breakthrough came on 15 minutes as Griffiths chased a ball down the right channel and, just when it looked like it would run out of play, the striker slid it expertly past a hesitant Zwick.
The second goal followed from the head of Boyata, who did well to lose his man in the box and bullet the ball home.
If there was any doubt about the game being over as a contest after that, Commons provided the clarity from the penalty spot just minutes before the break.
Scott Fraser brought down the hugely impressive Keiran Tierney and the man who was furious about being subbed in Norway was celebrating with the fans after blasting high past Zwick.
The second half started as the first ended, with Celtic in full flow and United pressed firmly against the ropes.
The visitors were on the canvas for a fourth time courtesy of a Commons cracker just before the hour.
The current fans' favourite found a yard of space just inside the penalty area and curled the ball expertly into Zwick's top right hand corner.
If the midfielder was making a point after the midweek spat with the Celtic bench, it was point proven.
He was substituted shortly afterwards but this time, instead of snarling in disgust, he applauded the fans and embraced his manager on the touchline. What a difference a few days and a few goals make.
Talking of goals, there was one more to come.
Celtic captain Scott Brown danced his way forward from the left with just minutes to go and his powerful strike on the angle was deflected into the net by Aaron Kuhl.
- 5SimunovicBooked at 73mins
- 15CommonsSubstituted forRogicat 65'minutes
- 14S ArmstrongSubstituted forMcGregorat 73'minutes
- 9GriffithsSubstituted forCiftciat 65'minutes
- 16TelferSubstituted forMurrayat 66'minutes
- 22FraserBooked at 45minsSubstituted forConnollyat 90+1'minutes
- 30BodulSubstituted forTaggartat 55'minutes
- Craig Thomson
- Shots on Target
Second Half ends, Celtic 5, Dundee United 0.
Foul by Nadir Ciftci (Celtic).
John Rankin (Dundee United) wins a free kick on the right wing.
Substitution, Dundee United. Aidan Connolly replaces Scott Fraser.
Own Goal by Aaron Kuhl, Dundee United. Celtic 5, Dundee United 0.
Attempt missed. Nadir Ciftci (Celtic) header from the centre of the box is just a bit too high.
Corner, Celtic. Conceded by Sean Dillon.
Corner, Dundee United. Conceded by Efe Ambrose.
Corner, Dundee United. Conceded by Dedryck Boyata.
Hand ball by Gary Mackay-Steven (Celtic).
Corner, Celtic. Conceded by Aaron Kuhl.
Attempt saved. Jozo Simunovic (Celtic) right footed shot from outside the box is saved in the bottom left corner.
Substitution, Celtic. Callum McGregor replaces Stuart Armstrong.
Jozo Simunovic (Celtic) is shown the yellow card for a bad foul.
Foul by Jozo Simunovic (Celtic).
Billy McKay (Dundee United) wins a free kick in the attacking half.
Attempt blocked. Tomas Rogic (Celtic) left footed shot from outside the box is blocked.
Foul by Tomas Rogic (Celtic).
Aaron Kuhl (Dundee United) wins a free kick in the attacking half.