Romelu Lukaku -- one of the best soccer players in the world -- was arrested in Beverly Hills after cops came to his mansion 6 TIMES for an out of control rager, TMZ Sports has learned.

It's unclear why the Everton star was in L.A., but law enforcement sources tell us he was renting a home in Beverly Hills while a bidding war is reportedly raging over him in Europe between 2 of the most famous soccer clubs on Earth.

FYI, Manchester United and Chelsea have both reportedly offered $100 MILLION to transfer the 24-year-old away from Everton ... but so far, the deal has yet to close.

In the meantime, we're told Lukaku threw a massive day party at his BH crib on July 2 that REALLY pissed off his neighbors ... triggering multiple complaints to the Bev Hills PD.

We're told cops went to the home at least 6 times to warn Lukaku to keep down the noise -- but he didn't listen and cops eventually arrested him for misdemeanor disturbing the peace.

Lukaku was not brought to the police station or formally booked -- instead, he was merely given a citation.

No word on what kind of punishment he faces -- but if it's a fine, dude can definitely afford it.