Santa Claus helps Celtic celebrate Scottish title
St Mirren captain Mark O'Hara twice gave the visitors the lead at Parkhead but goals from Matt O'Riley and Kyogo Furuhashi meant Celtic were level come half-time.
And when Palma turned in Anthony Ralston's cross in the 86th minute, home fans were able to roar on Celtic ahead of the trophy presentation.
A figure clad in the traditional Santa Claus costume then delivered the trophy -- six months after being booed while doing the half-time prize draw during a defeat by Hearts.
Palma's goal led Celtic manager Brendan Rodgers to take off Joe Hart, with supporters giving the 37-year-old a rousing ovation in what was the former England goalkeeper's final league game of his career.
Hart will now try to lift the seventh trophy of his three-year stint at Parkhead when Celtic face Glasgow arch-rivals Rangers in next week's Scottish Cup final.
'Just reward for Santa Claus'
Rodgers, in his second spell as Celtic manager, said: "Today was a brilliant Celtic day. The sun was shining, Santa Claus gets his just rewards in the end, and it was just a really special day."
Winning the Premiership title will also help Rodgers, who returned to Glasgow 11 months ago, to repair a relationship with Celtic fans damaged by his decision more than four years ago to join Leicester in mid-season.
"I just didn't want how I left, and the reaction to that, to be the big full stop on my Celtic story, because this club means everything to me," said Rodgers, 51.
The Northern Irishman added: "Growing up, supporting it, understanding the history of the club and what it means to so many people. I didn't want that to be the story. So I was really determined to come back, to have even more success this time around."
Celtic kicked off having already secured their 54th Scottish league title -- their 12th in 13 years -- with a 5-0 win at Kilmarnock on Wednesday.
But O'Hara damaged the paty mood when he opened the scoring in the seventh minute.
O'Riley equalised in the 21st minute but six minutes later St Mirren were ahead again, O'Hara scoring from the penalty spot after Celtic defender Stephen Welsh fouled Toyosi Olusanya inside the box.
Celtic equalised again eight minutes before the break when Furuhashi turned in fellow Japanese star Reo Hatate's cross at the near post.
Second-placed Rangers were held to a 3-3 draw by Hearts, who scored with the last kick of the match at Tynecastle.
Lawrence Shankland gave Edinburgh club Hearts, already assured of third place, the lead in the first half only for Rangers to score three goals without reply after the break through Ross McCausland, Todd Cantwell and Fabio Silva.
But Dexter Lembikisa's strike revived Hearts late on and they equalised deep into stoppage time thanks to Kyosuke Tagawa's superb volley.
But the longstanding gap between the Old Firm and the rest of the Premiership was evident from the fact Hearts finished a huge 17 points behind Rangers, who were themselves eight points adrift of Celtic.
Dundee and Kilmarnock drew 1-1 at Dens Park in Saturday's other Premiership match.
Gary MacKay-Steven fired Killie ahead in the 24th minute before Luke McGowan equalised for the hosts 13 minutes later.
Robbie Deas's second yellow card, in the 84th minute, reduced Kilmarnock to 10 men and four minutes later McCowan missed a penalty.