Celtic's 69-game unbeaten domestic run, ended emphatically by Hearts on Sunday, may never be surpassed, according to manager Brendan Rodgers.
The Tynecastle side hammered Celtic 4-0, inflicting their first defeat by a Scottish opponent since May 2016.
The Scottish champions broke their own 100-year-old British unbeaten domestic record of 62 games in November.
"They've set a record that may well never be beaten and they can be very proud," Rodgers told BBC Scotland.
"We hit the reset button and look to get three points in our next game.
"Now that the run is finished, we want to get back to winning ways as quickly as possible."
Celtic appeared unsettled and were slapdash in possession under heavy pressure from Hearts' aggressive pressing.
Sixteen-year-old Harry Cochrane, then former Rangers striker Kyle Lafferty, drilled home first-half goals, with Manuel Milinkovic striking twice after the break.
The loss is Rodgers' first domestic reverse since taking charge for the 2016-17 campaign.
"First of all, I need to give credit to Hearts," the former Liverpool boss said. "It's a thoroughly deserved win; they were the better team.
"We didn't cope with their physicality in our backline, we made too many mistakes.
"We could have played five games today and not scored a goal.
"But I also want to congratulate my players. To have gone through 69 games and this to be their first defeat; of course it's a sore one when you are beaten like that but they can hold their heads up.
"They have been absolutely amazing over those 18 months."
The tall figure of Lafferty was the focal point for Hearts' attack, with the Northern Irishman's aerial prowess allowing his midfield colleagues to power forward.
"We didn't cope with the direct balls from Hearts," Rodgers admitted. "It's a difficult pitch so of course they were not going to want to play on the floor.
"Lafferty was a problem for us, first half in particular, with his physicality. We made too many mistakes, basic errors, when to play and when to defend properly. I think three of the goals came from our players slipping.
"We did our very best and unfortunately our best wasn't good enough. We'll need to learn from the game and look to win our next one."
Under Rodgers, Celtic won their sixth successive Scottish Premiership title last season, completing the hat-trick of domestic trophies with the Scottish Cup and Scottish League Cup.
They have already retained the League Cup this term, beating Motherwell in November's final.
After the final whistle, the Celtic boss and his players formed a huddle on the pitch, with Rodgers saying he was eager for the squad to reflect on the pain of defeat, and the magnitude of their achievements.
"I know the disappointment and the honesty of the group," he said. "It was just a case of saying remember what this feels like - that obviously hurts - but also to remind them that what they've done is absolutely incredible.
"This day was always going to happen. It's over now and we need to get ready to go again."