KIERAN TIERNEY grabbed his first Celtic goal to kick start the Parkhead club’s trophy celebrations with a 7-0 mauling of Motherwell.

The 18-year-old, who hails from the Lanarkshire town, opened the scoring on 21 minutes before Tom Rogic and Mikael Lustig added another two within seven minutes.

Stuart Armstrong smashed in a fourth just a few minutes after the break just a few moments before Ryan Christie and Patrick Robert capped off impressive displays with a strike each.

However, there was still time for history to be made as debutant Jack Aitchison, becoming youngest ever Celtic player at 16 – grabbed the seventh with his first touch.

It brings Ronny Deila’s two-year tenure as Celtic manager to an emphatic end as the Norwegian bowed out in the Glasgow sunshine with warm applause from the bumper home supporter inside Parkhead.

For Motherwell, it was a painful end to a campaign that will see them finish fifth in the Ladbrokes Premiership.

The Steelmen are the only top flight opponents to have won at Celtic Park this season – coming in a 2-1 victory back in December – but this will go down as one of their worst performances since Mark McGhee’s return.

It didn’t take long for the party to get started. With top goalscorer and player of the year Leigh Griffiths suspended, it was Ryan Christie who was given the rare opportunity to be the lone striker for Celtic.

However, it was the contribution of those around him that made the difference here.

Despite a few early threats and impressive saves from outgoing Motherwell goalkeeper Connor Ripley, the deadlock was broken on 21 minutes.

The ball was worked out to Tierney on the left side who was allowed to ghost inside, shuffle the ball on his right foot and drive a low shot in beyond Ripley’s near post from the edge of the box.

Five minutes later it was two. A pass through was intercepted by the Motherwell defence but a short pass back to Ripley allowed Armstrong to nip in. His low shot beat the Well keeper only to come back off the post, but Rogic was on hand to turn it in.

More poor defending gifted Celtic a third. A deep corner from Armstrong caught out Ripley under the ball and with him out of position Lustig’s back post header flew into the net between the legs of Morgaro Gomis and into the net.

At half-time McGhee made two defensive changes as Luke Watt and Lionel Ainsworth were sacrificed for Joe Chalmers and Kieran Kennedy.

It didn’t make any difference as within five minutes of the restart the home side grabbed a fourth through Armstrong, who demonstrated terrific technique to lash a right-foot volley high beyond Ripley.

Celtic kept coming and so did the goals. On 55 minutes Roberts grabbed his goal. The ball was sprayed across to him on the edge of the Motherwell box and the on loan Manchester City man turned it on to his preferred left and bent the ball low into the bottom left corner from 20 yards.

Four minutes later and any meagre resistance Motherwell had shown gave way. A neat interchange opened the heart of their backline right up to play in Christie for his first Celtic goal, slipping it calmly under Ripley.

On came Aitchison and within seconds he wheeled away in celebration. A pass was cut out by Stephen Pearson but he inadvertently diverted it straight to the teenager unmarked in the box, and he showed great composure to turn it in.