Pep Guardiola and Thomas Tuchel meet in the latest edition of a rivalry that has taken in Bayern Munich v Mainz, Bayern v Borussia Dortmund, Manchester City v Chelsea and now City v BayernThe real business end of the Champions League starts this week with the final eight going head to head in the quarter-final first legs.
With more teams left from Italy than any other country and Benfica also through to the latter stages, there is a different shape to recent years.
Could we be in for a surprise winner and how might Chelsea and Manchester City, the Premier League's remaining representatives fare?
BBC Sport looks at some of the key talking points.
Manchester City v Bayern Munich - Guardiola v Tuchel again
Man City 0-1 Chelsea: 'It was the best or worst first meeting' - Tuchel on finally meeting AbramovichGuardiola goes back to face his old club for the first time since leaving Bayern Munich for Manchester City in 2016.
He was expecting to face a Julian Nagelsmann team again (having beaten his Hoffenheim twice in 2018-19), but the German side recently sacked him and appointed Thomas Tuchel - a name Guardiola is even more familiar with.
The managers have met 10 times before during a decade-long rivalry with Guardiola winning six and Tuchel three - those successes all coming in a six-week spell between 17 April and 29 May 2021.
That run - which included Chelsea's FA Cup semi-final and Champions League final wins over City - led to a feeling that Tuchel had the edge on Guardiola. In that final Guardiola famously did not play a defensive midfielder in a tactical gamble that failed.
But City beat Tuchel's Chelsea twice in the Premier League last season, and with four wins and a draw in Germany, including the 2016 DFB-Pokal final, Guardiola actually has the much better record.
Guardiola has had a mixed time against his old clubs. He has faced Barcelona four times since leaving - twice with City and twice with Bayern. He won two of those, but the other matches were 3-0 and 4-0 defeats.
Real Madrid v Chelsea - can Lampard do a Tuchel?
'This is my club' - Lampard on his Chelsea returnIn 2020-21, Chelsea started the season with Frank Lampard in charge and ended it with Tuchel leading them to Champions League glory.
In 2022-23 Chelsea started the season with Tuchel in charge and will end it with Lampard hoping to lead them to Champions League glory.
Lampard is the fourth man to manage Chelsea this season after the sacked Tuchel, the sacked Graham Potter and brief interim boss Bruno Saltor.
He is hoping to keep up an unusual club tradition, winning a European trophy in the first season of his reign - although unlike the others this is his second spell in charge.
Remarkably (even allowing for their love of chopping and changing bosses) Chelsea's last five European trophies have all come with managers who had taken over that season.
Four of those five took during the season, three of them after Christmas.
Potter may have hoped to join that club but he was sacked last week, with Bruno briefly having that opportunity too - he had initially been expected to be in charge until the end of the season.
In 2022 it was Potter's predecessor Tuchel and the Champions League. The German had taken over in January.
Italian Maurizio Sarri won the 2019 Europa League in his only season as Chelsea boss.
Former Liverpool boss Rafael Benitez led Chelsea to the 2013 Europa League, having been interim manager from November.
The season before, Roberto di Matteo had been interim boss for less than three months when he took them to 2012 Champions League glory.
And in February 1998 the late Gianluca Vialli was made Chelsea player-manager and guided them to a European Cup Winners' Cup victory that summer.
Dave Sexton is the only Chelsea manager to win a European trophy more than a year into his reign, the 1971 Cup Winners' Cup.
So can Lampard, who won the 2011-12 Champions League as a Chelsea player, add his name to that list?
In their way in the quarter-finals are European royalty Real Madrid, although Chelsea have a good record against them - losing only once in seven meetings.
That is the lowest percentage of losses against Real (14%) of any side to have played them at least five times in Europe.
AC Milan v Napoli - can Kvaratskhelia keep amazing season going?
Kvaratskhelia and Napoli have beaten AC Milan and lost to them this season in Serie AKhvicha Kvaratskhelia is a remarkable throwback and something which seemed impossible in modern football.
Nine months ago the average football fan would never have even heard his name, with all Kvaratskhelia's football being played in the Georgian and Russian leagues plus two Europa Conference League appearances.
And now the Georgian winger is genuinely a superstar and one of the form players in one of the best teams in European football, Serie A's runaway leaders Napoli.
In Serie A, Kvaratskhelia has 12 goals - only behind four players - and 10 assists - more than anybody else.
Paris St-Germain duo Lionel Messi and Neymar, Eintracht Frankfurt's Randal Kolo Muani and Arsenal forward Bukayo Saka are the only other players to have double figures for both goals and assists in Europe's top five leagues.
In the Champions League nobody has more than Kvaratskhelia's four assists.
Kvaratskhelia and Napoli will be hopeful that story can continue with a relatively kind quarter-final draw - against AC Milan, who sit 22 points below them in the table. However Milan did beat them 4-0 earlier this month.
Inter Milan v Benfica - can anyone stop Schmidt's side?
Benfica forwards Joao Mario and Goncalo Ramos are the top two scorers in the Portuguese league this seasonYou would not know this was a Benfica team who sold over £200m worth of talent this season.
First it was star striker Darwin Nunez to Liverpool for a fee of between £64m and £85m - and then midfielder Enzo Fernandez to Chelsea for £107m. More than 30 other players have left the club this season.
And yet under German journeyman manager Roger Schmidt, they look almost unbeatable.
In 46 games in all competitions since appointing the former PSV boss in the summer they have only lost twice - however one of them was on Friday at home to Porto.
They finished top of a Champions League group involving PSG and Juventus, picking up 13 points more than the Italians - and then blew away Club Bruges in the last 16, costing Scott Parker his job.
They are seven points clear of Porto at the top of the Portuguese league as they close in on a first trophy since 2019.
Only Italian teams stand between them and a first European Cup final since 1990, with the winner of their tie against Inter playing AC Milan or Napoli in the semi-finals.
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