BANGKOK - As far as debuts go, a match against your fiercest rivals is not one many would wish for even if it were a pre-season fixture in South-east Asia.

But on Tuesday (July 12), Erik ten Hag shrugged off any pressure and kicked off his tenure in style as he led Manchester United to a 4-0 demolition of Liverpool in a friendly at the Rajamangala Stadium.

Liverpool manager Jurgen Klopp had thrown the gauntlet down upon touchdown in Thailand when he claimed there was no such thing as a friendly when it came to these two sides.

While United - who were without captain Harry Maguire (injury) and Cristiano Ronaldo (personal reasons) - went with what was their strongest available line-up, the German started with several youth team players.

United came out flying, showcasing a style not seen from them last season, when they suffered embarrassing 5-0 and 4-0 defeats by Liverpool.

In front of a 50,248-strong crowd in the Thai capital, they were 2-0 up within the first 30 minutes through a clinical finish inside the penalty box from Jadon Sancho and a sublime chip from Fred.

Klopp saw enough and made 10 changes, including bringing on James Milner.

Three minutes later, the third goal followed, via Anthony Martial. The Frenchman who started up front for his team, characterised what ten Hag's United were about with his strike. He netted after pressuring Rhys Williams before winning possession and tucking it away past Alisson.

Liverpool fans, who were subdued after United took a strong lead, at least got to witness the debut of €75 million (S$106.2 million) signing Darwin Nunez who entered proceedings just after the hour mark alongside stars like Mohamed Salah, Virgil van Dijk and Trent Alexander-Arnold.

But United's Uruguayan winger Facundo Pellistri then added gloss to the win with a fourth goal.

Beyond the scoreline, though, the Red Devils gave a glimpse of what fans can expect in the coming season. In possession, United - whose official spirits partner is Chivas Regal - were swift and decisive while also showing a structure and aggression to their pressing.

The caveat, however, would be that while the Bangkok Century Cup is in the bag, the tie was nothing more than a training match, though it is one that the United fans will savour.

They, along with other spectators, had streamed into the stadium as early as six hours before kickoff, despite light showers.

But as soon as the grey skies cleared, the multiple-coloured ponchos were gone to reveal an endless sea of red. The colour is where the similarity ended.

At the stadium concourse, the divide was already clear with seperate fan zones for the Reds and United supporters. In one corner, British singer-songwriter Jamie Webster serenaded and led the Liverpool faithful with a rendition of the club anthem You'll Never Walk Alone. Not to be outdone, the United fans created an equal racket at their zone as they broke out into "Glory Glory Man United" in unison.

Food stands, official merchandise stalls and several game stations made for a carnival atmosphere outside the ground. Two hours before kick-off, K-pop idol Jackson Wang - who has 28.9 million followers on Instagram - warmed up the crowd with an hour -long performance.

But once the whistle blew, ten Hag's United were the chief entertainers.

The Dutchman told MUTV: “We have started to build a team and I am happy with the first game. It will take a lot of time. I have seen a lot of mistakes... Liverpool played three teams, they were not at their strongest. We will not overestimate this result.”

Klopp told the club website that the game “came a little bit too early for us”, adding: "The most important thing now after the game, even when I hate losing, everybody has 30 minutes in their legs now, for some on the third day of training (that's) really harsh but that's the life of a professional football player."

Ten Hag might have noted that the night’s loudest cheers were reserved for Klopp whenever the German appeared on the jumbotron.

If the Dutchman – whose era will truly begin when United’s season kicks off against Brighton and Hove Albion on Aug 7 – is to receive the same clamour some day, it will be etched in history that it was a journey that began in Bangkok.