Bayern Leverkusen's remarkable 51-game unbeaten run in all competitions has ended in dramatic fashion, drawing some inevitable parallels between it and the 'Invincibles' run Celtic enjoyed in 2016/17.
Having already clinched the German Bundesliga with five games to go and, at the time of writing, wielding a 17-point gap between first and second place, Xabi Alonso's men entered the UEFA Europa League final against Atalanta in fine form.
An Ademola Lookman hat-trick, however, ensured the Italian Serie A outfit prevailed on the night in what was ultimately a one-sided game somewhat against the odds.
Afterwards, Leverkusen manager Alonso simply said it wasn't to be, and that he and his players would dust themselves down and go again this Saturday in the German Cup final.
Such is the unforgiving nature of football that milestone moments are worth celebrating, but fleeting while still in the throes of a domestic campaign.
Celtic's unprecedented 'Invincibles' treble of 2016/17 was a similar endeavour, with an unbeaten domestic streak that stretched into the first half of the following season.
The question is: how does Bayer Leverkusen's unbeaten run compare to Brendan Rodgers and Celtic's Invincibles?
Celtic unbeaten run compared to Bayer Leverkusen
League
During the 2016/17 season, Celtic won 34 of their 38 games, drawing just four and, of course, losing zero. All told, Celtic played 56 Scottish Premiership league games, winning 47 and drawing nine, throughout their unbeaten run that extended into the 2017/18 season.
Standout results included two 5-1 wins over Rangers - one at Celtic Park in September 2016, the other at Ibrox in April the following year.
Of their 34 league games player, Bayer Leverkusen drew six. With a goal difference of +65, Xabi Alonso's side played entertaining football throughout - with second place Stuttgart's tally sitting at 39.
In Bayern Leverkusen's 51-game unbeaten run in all competitions, 34 unfolded in the Bundesliga.
Cup
Celtic's unbeaten cup run saw them clinch a historic and unprecedented four consecutive domestic trebles. During their unbeaten domestic run, however, this saw them lift the League Cup and the Scottish Cup during the 2016/17 campaign, and the 2017/18 League Cup, before ultimately losing their domestic streak in December 2017.
Bayer Leverkusen have confidently made it all the way to the German Cup final, which takes place on Saturday, May 25 against FC Kaiserslautern.
Europe
Celtic's 69-game unbeaten run applies to domestic competition only. Despite some great results during the 2016/17 UEFA Champions League campaign, not least home and away draws against Pep Guardiola's Manchester City, Brendan Rodgers' side suffered big defeats to the likes of Barcelona and Paris Saint-Germain.
Bayer Leverkusen's unbeaten run did encompass European football, and led them all the way to the UEFA Europa League final on Wednesday, May 22. This saw them string together an impressive 12 wins before succumbing to Italian Serie A side Atalanta in the competition's ultimate stage.
Close calls
Celtic's closest calls during their 69-game unbeaten run came with draws in the Scottish Premiership. Before breaking their streak, Brendan Rodgers' side had draw five games in the first half of the 2017/18 campaign, with the manager later reflecting on the possibility of a psychological barrier that restricted Celtic's play around that time.
Similarly, Bayer Leverkusen's closest calls ended in draws - with one particularly dramatic match being the German side's Europa League semi-final second leg against Roma. 2-0 down with eight minutes of normal time remaining, Xabi Alonso's men pulled one back via an OG, before Josip Stanisic drew level with 97 minutes on the clock.
The end
Celtic's 69-game unbeaten domestic run ended with a comprehensive 4-0 defeat against Hearts at Tynecastle on December 17, 2017.
Bayer Leverkusen's 51-game unbeaten run in all competitions ended with a similarly one-sided defeat when Atalanta swept them aside 3-0 in 2024 UEFA Europa League final.
