Newly-crowned champions Celtic dropped points for only the third time this season as they were held to a 1-1 draw by Partick Thistle at Parkhead.
The much-changed Glasgow giants, who claimed their sixth Scottish Premiership in a row with a 5-0 hammering of Hearts on Sunday, took a 50th minute lead through Sunday's hat-trick hero Scott Sinclair.
Thistle then stunned the home support when Ade Azeez grabbed a 64th minute equaliser.
Sinclair missed a chance to win it when his penalty was saved as Thistle held on for a result which tightens their grip on sixth spot and extends their unbeaten run to seven games.
Celtic manager Brendan Rodgers had no complaints about the draw.
"We were playing against probably the next best form team in the league along with Aberdeen, so we knew it was always going to be a difficult game for us," Rodgers said.
"I felt 1-1 was probably a fair result even though in the first half we had great control."
Thistle manager Alan Archibald was delighted after his side took their first point at Celtic Park since 1994.
"It looked a long way away in the first half. It was probably our worst performance here in terms of ball retention," Archibald said.
"It was much better in the second half. We're not there yet but it's in our own hands."
After clinching the championship, it was no surprise that Rodgers rested five key players for the match.
However, a few eyebrows were raised at Archibald's decision to make five changes to a side that had gone six games unbeaten.
The changes did little to dampen the mood of the Celtic fans packed into Parkhead who were in a celebratory mood, but despite strolling through the game the Hoops did little to get the party going in the initial stages.
Eboue Kouassi looked keen to impress on his first start since joining the Hoops in January. However, the 19-year-old was wildly off-target with a strike from distance after he broke forward from the half-way line.
Thistle, who packed their defence, frustrated Celtic with the champions' best effort of the half coming just before the break when Tomas Cerny was forced to palm away a fizzing shot from Nir Bitton.
Celtic needed some inspiration and it came from Patrick Roberts -- the architect of two of Sinclair's strikes in the thrashing of Hearts.
The on-loan Manchester City winger turned provider again as he rolled a pass into Sinclair's path that the former Aston Villa player dinked it over Cerny for his 22nd goal of the season.
A game that had been devoid of much action in the first-half then suddenly burst into life.
Tom Rogic came off the bench to replace Kouassi for the Australian international's first appearance since the middle of December due to an ankle injury while Emilio Izaguirre made way for Stuart Armstrong.
However, the pair had barely touched the ball before Thistle had grabbed an equaliser.
Izaguirre's departure meant Celtic had to reorganise their defence and Chris Elliot exploited this.
The Thistle midfielder burst into the box past Erik Sviatchenko before sending a low delivery into the six-yard box where Azeez applied a deft touch to divert it past Craig Gordon.
Celtic immediately responded and two minutes later were awarded a penalty as Gamboa was upended by Callum Booth.
Sinclair was handed the chance to add to his impressive tally but the 28-year-old's penalty was the perfect height for Cerny who palmed his effort away before the danger was cleared.
Elsewhere, Rangers' slim hopes of catching Aberdeen in second spot were dealt a major blow as the injury-hit Ibrox side were held to a goalless draw by Kilmarnock at Rugby Park that leaves them trailing the Dons, whom they face on Sunday, by 12 points.