Leicester rank among the best Champions League debutants after reaching the quarter-finals this season.
Only once in the Champions League era has a team appeared in the elite competition for the first time and gone on to the semi-finals, with last season's Premier League champions denied by Atletico Madrid in their bid to emulate Villarreal 11 years ago.
Here, Press Association Sport looks back over some of the other memorable campaigns by debutants.
The Spanish side ended Everton's hopes in the third qualifying round, and it was just the start of a stunning run to the last four for Manuel Pellegrini's Yellow Submarine. They twice held Manchester United to goalless draws in the group stage and saw off Rangers and Inter Milan in near-identical fashion, with away goals from Diego Forlan and second-leg winners from Rodolfo Arruabarrena. Only a solitary Kolo Toure strike over the two legs saw Arsenal into the final at their expense.
Pellegrini was again the man at the helm for the last debutants before Leicester to reach the last eight - and like the Foxes, Malaga began the season unranked in UEFA's classification of European clubs. They came through a play-off against Panathinaikos, beat AC Milan in the highlight of their Group C schedule and overturned a first-leg deficit to beat Porto in the last 16. They held Borussia Dortmund 0-0 in their quarter-final first leg but lost a dramatic return 3-2 after stoppage-time goals from Marco Reus and Felipe Santana.
DEPORTIVO LA CORUNA, 2000-01
Depor made an immediate impact in their early years in the Champions League, starting in their maiden campaign when they finished top in both group stages before a quarter-final exit to Leeds. A 2-0 second-leg win on that occasion was not enough after losing the opener 3-0, but provided a precursor to their comeback from a 4-1 first-leg loss to Milan three years later to reach the semi-finals.
The Rome side's rise throughout the 1990s culminated in 2000 with a domestic league and cup double and a run to the last eight in their first appearance among Europe's elite. They topped Group D in the second group stage against Chelsea, Feyenoord and Marseille before losing to Valencia in the quarter-final after Gerard's hat-trick in the first leg.
Guy Roux's remarkable 44-year reign as Auxerre manager saw him lift the club from the amateur third tier to Ligue 1 champions in 1996, earning them a place in the Champions League for the first time. They finished as Group A runners-up, level on points with Ajax, but were beaten in the quarter-finals by eventual champions Dortmund.
CELTA VIGO, 2003-04
On what is still their only appearance in the competition - when they, Depor and Real Sociedad joined Real Madrid in an unusual field of Spanish entrants - Celta came through a group containing both AC Milan and Ajax, in the process winning at San Siro. Arsenal ended their fun after a confusing first leg for commentators - Edu's goal for Celta overshadowed by two from his Arsenal namesake in a 3-2 Gunners win, which became 5-2 on aggregate.