Jozo Simunovic (centre) scored for the second weekend running
Celtic secured an eighth consecutive title in style with a convincing win away to third-placed Aberdeen.
Neil Lennon's side are now two-thirds of the way towards a third consecutive clean sweep of domestic trophies after already lifting the League Cup.
The Dons' James Wilson fired wastefully against a post before Mikael Lustig's diving header opened the scoring.
Jozo Simunovic rose to meet a Callum McGregor corner after half-time before Odsonne Edouard fired the third.
For Celtic not to have finished the weekend as champions, Aberdeen would have had to have ended the visitors' 11-game unbeaten run, combined with a win for second-placed Rangers at home to Hibernian on Sunday.
But the Glasgow side's sixth consecutive win at Pittodrie means they have now won eight domestic trophies in a row before their Scottish Cup final appearance against Heart of Midlothian.
Celtic will now eye matching the nine titles in a row they last achieved in 1974 and which was matched by city rivals Rangers in 1997.
Aberdeen remain in a battle for fourth with Kilmarnock, the Ayrshire side being three points behind ahead of their afternoon visit to Tynecastle.
Celtic make Dons pay for wastefulness
As a club, Celtic have experienced great sadness in recent weeks with the loss of two of their precious Lisbon Lions. The tributes have flooded in from all corners for Billy McNeill and Stevie Chalmers. The lives of two great footballers who helped lift the European Cup have been celebrated in word and song and that carried on at Pittodrie.
Another minute's applause but most importantly, given what these men represented, another victory and another league title secured. Eight in a row was never in doubt, but it was banked here.
Celtic survived a few scares but cantered away to win handily. Indeed, that could be the story of their season. Some wobbles but easy enough in the end, a league won largely in third gear.
The Dons could have delayed the inevitability of the title party, but teams don't tend to beat Celtic in domestic competition while spurning big moments. How the Dons will rue the early chances they had. How Derek McInnes, sitting in the purgatory of the stand while serving his touchline ban, will have suffered angst at what might have been.
These weren't half chances or 50-50 affairs. These were borderline sitters, both of them falling to James Wilson, a striker who finished like strikers tend to do when they're not used to scoring goals. Wilson, big on reputation but low on end product, can only boast 13 goals in a career that spans almost 90 games.
Celtic had the lion's share of possession, but it was the Dons who carved out the most interesting opportunities before Lustig got the Celtic party started. The first of them came when Scott Brown was hustled and harried and gave the ball away in the process.
Aberdeen swept left and, when Greg Stewart's cross came in it fell to Wilson, standing all alone and so close to Scott Bain that he could have heard him gulp. His volley was thumped into the ground and bounced up and over the Celtic goalkeeper's crossbar.
Edouard wasted a decent chance soon after, but another huge moment followed. This was the second act of wastefulness from Wilson. Scott McKenna did wonderfully to win the ball before bombing down the left and curling a gorgeous ball across goal and into the path of Sam Cosgrove.
The striker's shot was beaten away by Bain, but when the loose ball broke to Wilson, it looked certain that the Dons were about to take the lead. Instead, Wilson struck his shot off the outside of Bain's right-hand post and wide.
It was a calamitous miss and, sure enough, Aberdeen were made to pay for it, just as Kilmarnock were made to pay for not executing at Celtic Park last week when the game was still goalless. Looking gift horses in the mouth is not the best plan against the champions.
Seven minutes after Wilson's miss, Lustig got away from Stevie May and dived to head in McGregor's excellent delivery from the left. It was yet another assist for McGregor, a titan of this team - and there'd be a second one later on.
Lustig's terrific finish was the cue for the celebrations. Celtic only needed a point to lock down the title. They cruised on to take all three.
Celtic doubled their lead eight minutes into the new half. An out-swinging McGregor corner was headed home by Simunovic, the centre-half who, over the last few weeks, has showed the centre-forwards how to do it.
The hosts had a chance or two to halve the deficit but couldn't produce Celtic's efficiency in front of goal. They worked hard and got frustrated at times.
Cosgrove was fortunate not to be sent off when he brought down Jonny Hayes, who had appeared for Kieran Tierney. The full-back, still slightly diminished by injury, will now surely be wrapped in cotton wool before the cup final and that tilt for the treble treble.
Celtic's title day had a last flourish when they broke free and Edouard added a third, and a 21st for the season. That well and truly sent the visitors into raptures.
