Kris Commons bagged a brace as Celtic shrugged off European disappointment to extend their lead at the top of the Scottish Premiership to four points with a 5-0 thrashing of Dundee United on Sunday.

Commons was at the centre of controversy following his angry response to being substituted in the 3-1 Europa League defeat to Molde in midweek.

He made a public apology for his behaviour and buried a first half stoppage time penalty before curling home a 54th minute strike to put the melodrama behind him.

Leigh Griffiths had slotted home his 13th goal of the season from a difficult angle to give Celtic a 23rd minute lead before Dedryck Boyata headed home number two in the 40th minute.

Captain Scott Brown's 90th minute effort took a deflection off United's Aaron Kuhl for an own goal to seal the rout.

The win means leaders Celtic have a comfortable cushion over nearest rivals Aberdeen, who ended a three game losing streak with a 1-1 draw against Motherwell on Saturday, ahead of their clash at Parkhead next Saturday.

Celtic had made three changes from their midweek defeat to Molde with Jozo Simunovic, Kieran Tierney and Gary Mackay-Steven all handed starts.

There were a few eyebrows raised as Commons retained his place in the team, but the former Scotland international received a rapturous welcome from the home support and was first to test Luis Zwick with a shot on target.

The United keeper then had to dive low to his left to divert a dipping drive from former United midfielder Stuart Armstrong round the post.

Celtic continued to probe for an opening and Griffiths took advantage of some slack defending to fire the Hoops ahead in the 23rd minute.

Brown's pass was allowed to run by Sean Dillon and Griffiths nicked in ahead of Zwick to take a touch before finishing from an acute angle.

Celtic doubled their advantage five minutes from the break through Boyata.

Armstrong swung in a free-kick from the left to the near post where the Belgian met it with a glancing header that hit Zwick on its way in.

Commons then made it 3-0 from the penalty spot in first half stoppage time.

Tierney was upended by Scott Fraser after he burst into the box and Commons sent Zwick the wrong way as he slammed home the spot-kick.

Mackay-Steven hit the post almost immediately from the kick-off before Commons got his second of the match.

The 32-year-old collected a poor clearance and took a couple of touches to make room at the edge of the box before turning to curl a shot into the top corner.

Commons then came to Celtic's rescue at the other end when he cleared substitute Adam Taggart's effort off the line as he looked to make an immediate impact.

Brown was involved in the fifth in the 90th minute as he finished a mazy run into the box by sending a chipped shot past Zwick via a deflection off the head off Kuhl's head.