He defeated Carlos Takam in his 20th knockout win on Saturday night.

And world heavyweight champion Anthony Joshua, 28, celebrated with Hollywood A-listers Colin Farrell and Idris Elba, who were the first to show their allegiance.

The celebrities were also in the crowd at Cardiff’s Principality Stadium to see Joshua win with a 10th-round technical win.

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Undefeated: Boxing champion Anthony Joshua (right) is pictured greeting Idris Elba (left), who plays DCI John Luther on BBC’s Luther

Boasting his rock hard abs, Joshua was all smiles as he was joined by actor Idris, who has recently himself been trained in the ring.

For his series Fighter, Idris  recently trained to become a professional kickboxer, nurturing his life-long dream to fight.

The 45-year-old actor rocked a dark green biker jacket and ribbed jumper as the two posed for the cameras.

The undefeated boxer also greeted Irish actor Colin, who looked smart in a suave black blazer, which he accompanied with a classic white shirt.

Pals: Boasting his rock hard abs, Joshua was all smiles as he was joined by actor Idris, who was dressed in a dark green biker jacket and matching ribbed jumper

Happy trio: Anthony Joshua towered over actor Colin Farrell and his new ‘mystery girlfriend’, to whom he was seen getting cosy in the crowd on Saturday

The 41-year-old’s new mystery girlfriend was also in attendance, looking demure in a figure hugging, long-sleeved black top with a black blazer layered on top.

Colin and his new ombre-haired companion were seen cosying up in the crowd, earlier that evening.

As well as celeb fans Colin and Idris, many stars seemed to be in Anthony’s corner on Saturday as the well-known took to Instagram to share their excitement.

Reading for the match: Made In Chelsea’s Louise Thompson and Ryan Libby looked pumped as ahead of the fight

Fun times: YouTuber Joe Weller reflects on the knockout match as he captions the snap, ‘fun night at the boxing last night’

Star-studded event: Rapper Tinie Tempah was ringside as he took to Instagram to document the fight

In his first fight since ending the career of the great and once-dominant Wladimir Klitschko, 28-year-old Joshua required his advantages in size, speed and power to gradually wear down his previously little-known opponent from France.

Bigger fights against superior opponents are expected to follow in 2018 – but in defeating his mandatory challenger and excluding that with Klitschko, the Briton unexpectedly faced the toughest match-up of his career.

There were boos of disappointment about the premature ending among the cheers for another Joshua KO victory.

Anthony Joshua cemented his status as the best pound-for-pound heavyweight boxer on the planet by beating Carlos Takam

Flawless: The unknown beauty gazed lovingly into her Hollywood hunk’s eyes as she completed her look with a stunning pendant necklace

Luther is in the building! Idris Elba also made an appearance at the fight, where Anthony Joshua was taking on Carlos Takam in front of an anticipated crowd of 80,000

Following 10 rounds of high-energy boxing, Joshua emerged victorious after the referee brought an end to the contest

Takam couldn’t hide his disappointment at the stoppage as the ref called time on the fight and boos rang out around the arena