Hearts break spell but Celtic join Milan, Porto among unbeaten elite
Celtic's unbeaten run in the Scottish Premiership is finally over, but the Hoops can take pride of place among some illustrious sides.
An emphatic 4-0 win for Hearts on Sunday saw Celtic's unbeaten domestic run finally come to an end after 55 Scottish Premiership games without tasting defeat.
Outside of European competition, the Bhoys, who are chasing their seventh successive title this season, had not lost since going down 2-1 away to St Johnstone in May 2016.
Brendan Rodgers' side remain two points clear at the top of the table and can be confident of retaining their crown ahead of challengers Aberdeen and Rangers.
And while their streak is finally over, they can now rub shoulders with a select group of teams from across Europe to have orchestrated similar feats.
Here's a look at some of the other clubs to have held such mastery over their respective national league competitions....
AC Milan | 1991–1993 | 58 matches
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The Rossoneri of the late 1980s and early 1990s continue to be remembered as one of the best teams in modern football history.
Until Real Madrid's triumph over Juventus in the Champions League in Cardiff in June, they were the last side to retain the European Cup.
That achievement came under Arrigo Sacchi in 1989 and 1990, but it was his successor Fabio Capello who oversaw a 58-match unbeaten run in Serie A, which included marching to the 1991-92 Scudetto without suffering a single defeat.
Given Italian football's status at the time as the world's premier domestic football competition, Milan's achievement is hard to top.
10/05/1992 the Invincibles won the 12th Red and Black Scudetto... undefeated: 22 wins, 12 draws! May 10, 2017
Porto | 2010-2012 | 55 matches
Taking over from Jesualdo Ferreira and being followed by Vitor Pereira, coaching prodigy Andre Villas-Boas did not suffer a single league defeat during his time in charge of Porto.
The Dragons won the Primeira Liga, Portuguese Cup and UEFA Europa League in his lone campaign at the helm, before he resigned to take over at Chelsea.
Nicolas Otamendi, Fredy Guarin, Joao Moutinho, James Rodriguez, Radamel Falcao and Hulk all starred in a team that went 55 league matches unbeaten, surpassing Porto's previous best of 53.
That tally had been established between 1994 and 1996 by Bobby Robson, the Englishman who helped Villas-Boas to break into the world of elite football coaching.
Youngest UEFA club competition final winning coach?André Villas-Boas: 33 years, 213 days (Porto, 2011 ) February 11, 2016
Lincoln Red Imps | 2009-2014 | 88 matches
They might lack the standing of Milan or Porto, but Lincoln Red Imps deserve recognition for their marathon unbeaten league record in Gibraltar's Premier Division.
From May 9 2009 to September 19 2014, they avoided defeat in the competition.
At 1,959 days, it is - according to UEFA - the longest chronological unbeaten league run in European football and helped them to rack up 14 consecutive titles from 2002-03 to 2015-16.
And the name will be familiar to Celtic fans, Lincoln having stunned the Hoops 1-0 in Brendan Rodgers' first match in charge in July 2016.
The Scottish giants avoided an embarrassing exit from the second qualifying round of the Champions League by winning the second leg 3-0 in Glasgow.
Steaua Bucharest | 1986-1989 | 104 matches
The longest unbeaten league run in European football remains the proud property of Steaua Bucharest.
The Romanian powerhouse lasted an extraordinary 104 league games before finally losing and managed to win every one of their 15 Romanian Cup matches in that spell, making it a total of 119 unbeaten domestic fixtures.
Their dominance at home also translated to success on the continental stage, Steaua stunning Terry Venables' Barcelona on penalties to win the European Cup in Seville in 1986.