Leigh Griffiths bagged a double as Celtic hammered nearest rivals Aberdeen 3-1 to open up a formidable seven-point lead at the top of the Scottish Premiership on Saturday.
In an evenly-contested first half, Adam Rooney had his 24th-minute effort chopped off for offside before Griffiths headed Celtic into a 44th-minute lead.
The Scotland striker stroked home his second from the penalty spot in the 53rd minute after Kris Commons had been scythed down by Ash Taylor.
James Forrest prodded home a third in the 60th minute before Rooney headed in an 89th-minute consolation for Aberdeen.
"I am a very happy man just now," Celtic manager Ronny Deila said. "I am proud because we have played four games in nine days and that's very tough.
"We performed for 90 minutes and should have scored more."
It is a massive blow to the Dons, whose title challenge has been floundering in recent weeks after they at one stage held a five-point advantage over Celtic following their 2-1 win at Pittodrie in September.
Aberdeen manager Derek McInnes took some positives from the defeat, however.
"I thought in the first half there was a lot to be encouraged by and a lot of positive play," McInnes said.
"We had a nice compact shape and we created a lot of chances. How we only scored one here I do not know."
Following a frantic start, the first real opportunity of the match fell to the in-form Griffiths but the Hoops striker arrowed his shot narrowly wide.
Aberdeen responded with Rooney flicking a Niall McGinn cross from the right inches over the bar.
The Dons striker looked in the mood and minutes later dinked a Jonny Hayes delivery onto the roof of the net.
Aberdeen had the ball in the net in the 24th minute when Rooney stabbed home a cross from close range but the visiting fans' joy was short-lived as it was immediately ruled out for offside.
- Reflex save -
Some superb goalkeeping from Danny Ward kept the game goalless four minutes later when he rushed off his line and produced a magnificent reflex save to keep Griffiths' effort out.
Another chance came Rooney's way in the 35th minute with Hayes once again swinging a vicious delivery into the box but the striker's downward header bounced wide.
Kenny McLean then came to Aberdeen's rescue at the other end as he headed Dedryck Boyata's looping header onto the underside of the bar.
The deadlock was finally broken in the 44th minute through Griffiths. The Scotland striker ghosted in between Taylor and substitute Paul Quinn to get on the end of a deep delivery into the box from Kieran Tierney and bullet a header beyond Ward.
The chances kept coming in the second half with a shot from Australian international Tom Rogic stinging the palms of Ward before Commons sent an effort on the half-volley wide.
A reckless challenge from Taylor then saw Celtic awarded a penalty. The defender scythed down Commons on the far left-hand edge of the box and Griffiths expertly dispatched his spot-kick beyond Ward.
A fantastic finish from Forrest made it 3-0. The impressive Rogic drove at the retreating Aberdeen defence before threading the ball through to Forrest who took a touch before prodding past Ward.
Substitute Peter Pawlett then had his header stopped on the line before Rooney headed Hayes' cross past Craig Gordon to reduce the deficit late on.