They say revenge is a dish best served cold.

And on Tuesday, Bayern Munich did exactly that to avenge a 4-0 quarter-final first-leg loss to Barcelona in the Champions League four years ago.

“I remember that game well and I don’t really like to think about it because it was quite painful to watch,” said Bayern chairman Karl-Heinz Rummenigge ahead of the two sides’ meeting in Munich.

“However, it is a wonderful opportunity for us to show that we’ve improved a lot since then.”

That, they showed; ripping apart a Barca side to leave them with a mountain to climb ahead of their semi-final second-leg at the Nou Camp in eight days’ time.

It was a performance that left Rummenigge speechless.

“The team is fantastic,” he said. “I’ve never experienced such a night in my life and I’ve been around for a while.”

Last month, Barca had rendered several of their obituaries redundant.

The Catalans created Champions League history as they produced a rip-roaring display of attacking football to become the first team to come back from a 2-0 first-leg deficit to advance to the quarter-finals when they defeated AC Milan 4-0 at the Nou Camp.

But producing a similar performance next Wednesday is surely beyond them.

Surely not against a ballistic Bayern side which seems to be battering every opposition which comes their way as they look to redeem themselves for losing last year’s final at their own Allianz Arena.

Surely not against the team which looks set to take their mantle of Europe’s finest football team.

Tuesday’s tie was an era-defining one.

It was a match between a Bayern side utterly determined to show they can match, and outdo, the most revered club side there is and a Barca side regarded as the greatest team of its generation.

By the end, it was humiliation for Barcelona who were dealt their heaviest loss in a Cup competition since they were beaten 4-0 by Getafe in the Copa del Rey in 2007.

In the last four years, Barca and Bayern have reached two Champions League finals each with the former winning both and the latter losing both — their latest heartbreak coming last season to Chelsea.

It has made them even more resilient.

“It was a huge disappointment to lose the final at home, but we’ve learnt from that and come back much better, especially in this season's Champions League,” said Bayern captain Phillip Lahm in the pre-match news conference.

On Tuesday’s performance, they surely have as they simply bullied Barca into submission, beating the Catalans at their own game.

Barca were outpressed, outmanoeuvred and, ultimately, outscored by a Bayern machine at its optimal level, full of fluid counter-attacking, intelligent running and the appliance of good technique at pace.

A side of Barca's sophistication are not accustomed to being outplayed in this manner but Bayern did to Lionel Messi and company what they have been doing to others for years, giving them an idea of how it feels to be on the wrong end of a good old-fashioned thrashing.

It certainly was a chastening experience for La Liga champions-elect who had hoped get a boost from Lionel Messi, who returned from a hamstring injury sustained in the quarter-final against Paris St Germain.

But the tiny Argentine was virtually invisible all game and a shadow of his usual match-winning self with the injury clearly inhibiting his movement and his team miserably missing the intensity which brought their Champions League triumphs of 2009 and 2011.

It was an appalling display of their dependence on the Argentine World Player of the Year.

“We didn't get Messi into the game,” Barcelona defender Gerard Pique told TV3.

“He tried very hard and it was a great effort of his to be here but we just couldn't do any more.

“They thrashed us. It is almost impossible [to make a comeback], but we have to show face in the return leg.”

Bayern, meanwhile, played with the ambition, superiority and ruthlessness required to be European champions.

There were outstanding performances down the spine of the Bayern team with Dante, Javi Martinez and Bastian Schweinsteiger utterly controlling the central acres and even as they surrendered much of the possession, they frustrated Barca’s passing game before they could get close enough to create chances.

Barcelona could not get the ball, really only when picking it out of their net.

Thomas Muller scored twice and set up two others for Mario Gomez and Arjen Robben to turn it into a rout with the opening two strikes coming on set-pieces as the Bavarians dominated the air at the Allianz Arena.

Bayern can still reflect the winning margin should have been more when they think back on the chances they missed while Barca could feel hard done by after the referees missed an offside for Gomez’s goal and a clever block by Muller on Jordi Alba for Robben’s strike.

“We can be very proud, this Barca team has dominated Europe over the last five years and if you beat them like this in such terrific way I think you can be proud,” Robben told ITV after the match.

On their current form, Bayern are in a position to become the dominant force in European football. And if this was a shift of power from Catalonia to Bavaria, it was an emphatic one.

“We analysed Barcelona perfectly and took control and imposed our style of football,” said Bayern coach Jupp Heynckes. “I must say we did a fantastic job.”

Heynckes will leave Bayern at the end of the season for none other than former Barca coach Pep Guardiola — the man behind Barca’s five-year reign as Europe’s best side — to take over the hot-seat.

With Bayern having already secured the Bundesliga title and in the final of the German Cup, Heynckes might leave the Spaniard with a tough act to follow.

But with a squad due to be further strengthened by the arrival of Mario Goetze in the summer, he’ll leave him with a team well-equipped to start an era of domination of their own.