Atletico Madrid can make club history at Bayern Munich on Tuesday as the Spaniards look for a record sixth group stage win with both teams through to the last 16.
Diego Simeone's men arrive in Munich as the only side with a 100 percent record after five wins from five Champions League games.
The Group D leaders are six points clear of second-placed Bayern, who they beat 1-0 in Madrid in September, thanks to Yannick Carrasco's first-half winner.
Only five teams have achieved the feat of winning all six Champions League group stage games: Real Madrid (twice, 2011/12, 2014/15), AC Milan (1992/93), Paris Saint-Germain (1994/95), Spartak Moscow (1995/96) and Barcelona (2002/03).
The match at Munich's Allianz Arena is a dead rubber and regardless of the result Atletico will progress as group winners with Bayern second.
But Saul Niguez, who scored Atletico's winner in last season's home semi-final, said the Spaniards are taking nothing for granted.
"We still want to put on a top performance. We always want to win and fight for every title, but it will be difficult against Bayern," the defender said.
Bayern have their own record run to maintain in Munich as their 4-1 victory over PSV in October was their 14th straight home win in the Champions League -- a competition best.
'Matter of pride'
Regardless, Bayern want a good performance after their 3-2 defeat at Rostov last time out.
"It's a matter of honour and pride," Bayern midfielder Thiago Alcantara told Sky.
"Everyone wants to win and there is nothing better than winning against a team like Atletico."
Bayern also have a score to settle after September's defeat in Madrid and semi-final exit last season at the hands of Atletico and Antoine Griezmann.
Atletico lost last season's final to neighbours Real in Milan on penalties having squeezed past Bayern in the semis.
Madrid beat Bayern 1-0 at home and although the Germans won the return 2-1 in Munich last May, Griezmann's crucial away goal knocked the Bavarians out on a night when Thomas Mueller and Fernando Torres had penalties saved.
"The semi-finals were painful, but it's a thing of the past. Now we want a good performance," said Thiago.
Atletico's contrasting domestic and European fortunes so far this season continued as they were held to a 0-0 draw by Espanyol at home on Saturday.
The result leaves them nine points adrift of runaway Spanish league leaders Real Madrid.
Atletico have at least recovered their defensive solidity with four consecutive clean sheets following a 3-0 reverse to Real two weeks ago.
Simeone has named a full strength 20-man squad for the trip to Germany, but key players like Diego Godin, Carrasco and Griezmann could be rested for their crucial La Liga match at Villarreal next Monday.
Having won the Bundesliga title for each of the last four seasons -- a German league record -- Bayern find themselves in the unusual position of second in Germany's top flight, three points adrift of leaders RB Leipzig.
Head coach Carlo Ancelotti experimented for Friday's 3-1 win at Mainz.
He switched Thomas Mueller from the wing to the attacking midfield and opted for a 4-2-3-1 formation, rather than his prefered 4-3-3, which paid off as Robert Lewandowski netted either side of an Arjen Robben goal.
It was a return to winning ways after Ancelotti admitted his side made too many mistakes in the defeat to Rostov and 1-0 league loss at Borussia Dortmund last month.
"When we look at the stats, we haven't conceded many goals, but there were many individual mistakes we made and we're working on that," said Ancelotti.
The Italian says centre-back Jerome Boateng is out with a shoulder injury, while Arturo Vidal will feature at some point after returning from a leg injury he picked up playing for Chile.