Celtic produced a memorable first-half display to be almost certain of the three points against Dundee United at Tannadice.

Chris Sutton netted twice after Henrik Larsson had fired home a penalty to leave the Scottish Premier League's bottom club reeling at the half-time interval.

Martin O'Neill returned to the place where it all started for him as Celtic manager as his side came to Tannadice.

O'Neill enjoyed a winning start to his new career back in July and the Parkhead outfit have not looked back since as they currently sit a comfortable 10 points clear of Hibernian at the top of the Scottish Premier League.

But the former Leicester manager was forced to make one change from the side which took the points at St Mirren two days ago, with Jackie McNamara replacing the suspended Alan Thompson.

In contrast Dundee United's season has gone from bad to worse as they lie five points adrift of St Mirren at the foot of the table with just one victory this season in the SPL.

Manager Alex Smith made three changes from the side which lost at Hearts on Saturday with John McQuillan, Craig Easton and Steven Thompson coming in for the suspended Derek Lilley as well as Neil Heaney and David McCracken.

The home side were encouraged going into the game after holding third-placed Rangers to a draw here last week, but Celtic started the brighter of the two sides.

Bobby Petta shrugged off the close attentions of McQuillan and Danny Griffin in the fourth minute before lashing a shot over Alan Combe's crossbar to give the home side an early warning.

A minute later and United midfielder Hasney Aljofree became the first name in Hugh Dallas' notebook after a foul on Neil Lennon and then for a deliberate trip on Stilian Petrov.

Larsson then tried to catch Combe unawares with a free-kick in the eighth minute from a wide position just outside the box, but the keeper comfortably gathered despite a deflection off the United wall.

But United broke with pace and promise on the break and Celtic were let off the hook in the 13th minute.

Easton flighted the ball into the area and Jim Hamilton got up to head on target which Celtic goalkeeper Douglas did well to stretch and touch the ball around the post.

The goal again opened up for Hamilton in the 16th minute after Ramon Vega had knocked McQuillan's pass into his path, t skipper Johan Mjallby got a timely block on it to send it just over.

Moments later and Larsson was handed the best chance of the match as David Partridge let Douglas' clearance bounce and Larsson hit a right-foot shot from just inside the box that Combe did well to save.

The goal Celtic had been threatening finally arrived in the 23rd minute from the penalty spot after Aljofree was adjudged to have brought down Larsson in the box.

The Swedish international striker stepped up himself to blast the ball low and the pace took it past Combe and into the net for his 28th goal of the season.

Partridge became the next United man to receive a yellow card on the half-hour mark which was brandished for persistent fouling and the home side were starting to feel the pressure.

Sutton then should have hit the target in the 32nd minute when Vega picked him out unmarked at the far post but he somehow headed wide.

But the £6million striker made amends just two minutes later when Petta showed a great burst of pace to leave the United defence in his wake before sliding the ball across the face of goal for Sutton to side-foot home from close range.

Former Rangers player Charlie Miller was getting a hard time from the travelling Celtic support and he too was shown the yellow card for a reckless late tackle on McNamara.

The visitors were threatening to run riot and they almost added a third in the 38th minute when Didier Agathe skipped past the challenge of Aljofree before finding Larsson, whose volley was well saved by Combe.

But Celtic were refusing to show any Christmas spirit to their opponents and in the 41st minute they effectively wrapped up the points when Sutton rose to head Lennon's free-kick past Combe and into the top corner.