AC Milan (1992/93) W6 D0 D0 F11 A1
Milan were the dominant force in the early years of the UEFA Champions League and set the tone immediately, winning all four games against NK Olimpija Ljubljana and ŠK Slovan Bratislava in the first two rounds to reach the competition proper. They carried that form into the inaugural group stage, dispatching IFK Göteborg 4-0 on opening night with Marco van Basten famously scoring all four.
Their next four victories all came by a single goal, away to PSV Eindhoven, away and home against FC Porto and at IFK, before PSV were beaten 2-0 at San Siro as Milan reached the final. There they came up short, losing 1-0 to Olympique de Marseille in Munich. That remains the closest a side with a perfect group record have come to winning the UEFA Champions League.
Paris Saint-Germain (1994/95) W6 D0 L0 F12 A3
Paris did not look back after George Weah and Daniel Bravo scored in a 2-0 matchday one success over FC Bayern München, 2-1 victories away to both FC Spartak Moskva and FC Dynamo Kyiv putting them in control of their section. Weah then struck the only goal at home to Dynamo and away to Bayern, and added two more as Spartak were thrashed 4-1 in the concluding fixture.
While their winning run was curtailed by a 1-1 draw at FC Barcelona in the first leg of the quarter-final, Paris still progressed with a 2-1 home triumph. Milan proved too strong in the last four, however, prevailing 1-0 in Paris and 2-0 back in Milan.
FC Spartak Moskva (1995/96) W6 D0 L0 F15 A4
Spartak started with a pair of narrow wins, 1-0 at Blackburn Rovers FC and 2-1 at Legia Warszawa, before hitting their stride against Rosenborg BK on matchdays three and four. The Norwegian team were felled 4-2 in Trondheim – Spartak rallying from two goals down at half-time – before a 4-1 home success that preceded the Russian side's 3-0 home defeat of Blackburn.
Second-placed Legia were then edged out 1-0 in Poland as Spartak claimed their sixth straight victory to top the section by a record 11 points, but that was as good as it got. The winning streak was ended by a 2-0 reverse at FC Nantes in the quarter-final first leg, a 2-2 draw in the return confirming their elimination.
FC Barcelona (2002/03) W6 D0 L0 F13 A4
A 3-2 home success against Club Brugge KV on 18 September 2002 – current coach Luis Enrique opening the scoring – set Barcelona off on a sequence of nine straight victories, a UEFA Champions League record until Bayern achieved a new mark in 2013/14. The run took in home and away wins against Galatasaray AŞ and FC Lokomotiv Moskva, plus another slender triumph against Club Brugge, as Barça finished 11 points clear in their section, equalling CSKA's record, as Madrid have done this season.
There were also victories against Bayer 04 Leverkusen, Newcastle United FC and FC Internazionale Milano in the second group stage before the procession came to a halt with a goalless draw at Inter; the Blaugrana swiftly bounced back with two more wins, only to bow out to Juventus in the last eight.
2011/12: Real Madrid CF W6 D0 L0 F19 A2
Madrid could become the first team to win every game in a UEFA Champions League group stage twice, having won their section by ten points three years ago. José Mourinho's side opened with a 1-0 success at GNK Dinamo Zagreb and were unstoppable thereafter, brushing aside AFC Ajax 3-0 and Olympique Lyonnais 4-0 at the Santiago Bernabéu.
A 2-0 triumph in Lyon followed before Dinamo became the first – and only – opponent to breach Madrid's defence in the group; unfortunately, by then, the Croatians were 6-0 down. A 3-0 stroll at Ajax completed the perfect set of six for Madrid, who would fail to win for the first time at PFC CSKA Moskva in the round of the 16 first leg. The Spanish giants still got through the tie, and saw off APOEL FC in the quarter-finals, only to fall to Bayern on penalties in the semis. They will hope to go a step further having become the first club to register 18 points twice this time round.