Bayern Munich showed no mercy to amateurs Auckland City at the Club World Cup, beating the minnows from New Zealand 10-0 in their opening game as Jamal Musiala came off the bench to score a second-half hat-trick.

Kingsley Coman, Michael Olise and Thomas Mueller all netted twice, while Sacha Boey was on target too for the German champions in the game in Group C, which also features Boca Juniors and Benfica.

Harry Kane started but didn't get on the scoresheet before being replaced just after the hour mark by Musiala, who netted his three goals in the space of 18 minutes towards the end.

"We have to remain modest but it was important to be able to say that we took the game seriously," said Bayern coach Vincent Kompany. "It was a good first match at the tournament, but of course challenges are going to grow and it's going to become more difficult."

It was a stroll in the park in the midday sun in Cincinnati for Kompany's side, with France winger Coman scoring twice in the opening 21 minutes either side of goals by compatriots Boey and Olise.

Coman's sixth-minute breakthrough goal was the first of the tournament following the 0-0 draw between Inter Miami and Al Ahly in Saturday's opening game.

Mueller got the fifth and Olise's second of the afternoon made it 6-0 in first-half stoppage time for the Bundesliga heavyweights.

Olise's strike for the sixth was the pick of the day's goals, as he came in from the right before curling a shot on his left foot into the far corner.

Auckland City managed to stem the tide for much of the second half before Musiala came on and took centre stage, his three goals including one from the penalty spot after he had been fouled.

Mueller, who will leave Bayern after the tournament, made it 10-0 in the 89th minute with his 250th goal for the club.

The result confirmed the enormous gulf between one of Europe's giants and an Auckland side who have won the Oceania Champions League 13 times but whose amateur players had to take unpaid leave to travel to the United States for the tournament.

"This is the reality of football against one of the world's top teams," admitted City's interim coach, Ivan Vicelich.

"It is a dream for players coming from an amateur level to play in this environment," he added. "We knew it was going to be a very difficult game, playing against one of the top teams in the world, potentially one of the favourites for the Club World Cup, so we are just really proud of the players' efforts."

However the result made it an ideal start for Bayern, who won the Club World Cup twice in its former seven-team guise, in 2013 and 2020.

They have recorded bigger victories in the past in the German Cup, but the 10-goal winning margin equals their best ever in the Bundesliga, when they beat Borussia Dortmund 11-1 in 1971.

Bayern, who gave new signing Jonathan Tah a debut in central defence following his recent arrival from Bayer Leverkusen, play Boca in their next match in Miami on Friday.

Auckland City take on Benfica earlier the same day in Orlando.

Meanwhile, newly crowned European Champions Paris Saint-Germain launched their bid for Club World Cup glory with a convincing 4-0 victory over Atletico Madrid.

In searing heat at the Pasadena Rose Bowl east of Los Angeles, PSG proved too hot to handle for their Spanish opponents in an impressive opening Group B win.

Goals from Fabian Ruiz, Vitinha, Senny Mayulu and Lee Kang-In sealed the three points for PSG, who delighted a crowd of 80,619 with their adventurous attacking play.

The French giants picked up where they had left off in their 5-0 Champions League final mauling of Inter Milan a fortnight earlier, quickly settling into their smooth passing game to control the early exchanges.

Atletico goalkeeper Jan Oblak was soon pressed into action, blocking a Goncalo Ramos shot from just outside the box on 17 minutes as PSG's pressure mounted.

Oblak denied PSG again moments later, diving to stop a Khvicha Kvaratskhelia shot that was destined for the bottom left-hand corner.

Those early warning shots proved to be a precursor for the game's opening goal in the 19th minute.

A lovely passing move down the right saw the ball swiftly transferred to Georgian winger Kvaratskhelia who deftly laid off into the path of Ruiz to sweep in a low finish for 1-0.

With Atletico struggling to gain any kind of a foothold in the contest, the Spanish side's frustration began to show.

Clement Lenglet was booked for a rash challenge on Moroccan international Achraf Hakimi in the 21st minute, and Robin Le Normand picked up Atletico's second yellow soon afterwards for bringing down Ruiz.

Ruiz himself was booked on 28 minutes for a shove on Giuliano Simeone before the Argentine midfielder collected Atletico's third yellow soon afterwards.

With the Parisians in complete control, Atletico had to wait until the stroke of half-time before their first shot on goal, France's Antoine Griezmann drawing a smart save from Italy international Gianluigi Donnarumma with a low shot.

From the ensuing counter-attack, however, Atletico found themselves 2-0 down.

The electric Kvaratskhelia again found space down the left and fed inside to Vitinha, who ghosted into the box before steering a crisp shot beyond Oblak for 2-0.

Atletico appeared to have hauled themselves back into the game early in the second half when Julian Alvarez rifled home a low finish to make it 2-1.

But the goal was chalked off after VAR spotted a bodycheck by Argentine midfielder Rodrigo De Paul on Desire Doue in the build-up.

That effort appeared to buoy Atletico for the remainder of the half, but despite playing with greater intensity they were unable to create a single shot on goal.

Lenglet was dismissed after picking up a second yellow card on 78 minutes.

A disappointing Atleti display was summed up by a glaring miss four minutes later, substitute Alexander Sorloth somehow scooping over an open goal from a few yards out after Marcos Llorente's cross.

PSG swiftly made Atleti pay for that miss, substitute Senny Mayulu pouncing on a loose ball to make it 3-0 in the 87th minute. The rout was completed in injury time when Lee stepped up to convert a penalty after a handball by Le Normand.

PSG will face Brazil's Botafogo in their next group match in Pasadena on Thursday, before completing the first round against Major League Soccer's Seattle Sounders on June 23. (AFP)