Emotions are running high at New York fashion week this weekend, but not because of the clothes.

At a party hosted by magazine Harper’s Bazaar on Friday, rappers Nicki Minaj and Cardi B were involved in an altercation. In video footage, the pair are seen arguing and being kept apart by their entourages. Cardi B – wearing a distinctive red Dolce & Gabbana dress – is seen lunging towards a group of people, reportedly including Minaj. She was later seen with a bump on her head, said to be the result of being elbowed by a security guard, and barefoot after taking her shoe off to throw.

Cardi B was the first to take to social media, although she didn’t mention Minaj by name. She posted on Instagram a screenshot of a note including the words: “When you mention my child, you choose to like comments about me as a mother, make comments about my ability to take care of my daughter is when all bets are fuckin’ off!” The star and her husband, rapper Offset, had a daughter, Kulture Kiari Cephus, in July. Minaj has yet to comment.

Cardi B, with a bump on her forehead, leaves after an altercation at the Harper’s Bazaar party. Photograph: Charles Sykes/Invision/AP

Across town in Central Park, the Ralph Lauren 50th anniversary show was more serene, though still emotional, as thedesigner marked five decades of his eponymous label. Many famous friends and red-carpet regulars turned up. Kanye West, Oprah and Robert de Niro were all in the front row, as were fellow NYC designers Michael Kors and Diane Von Furstenberg.

Lauren’s spring/summer 2019 collection, which saw the park’s Bethesda Terrace transformed into a carpeted catwalk, was another celebration – of his brand’s style signatures. The western influences and cosy-meets-all-American cool it has made its calling card featured heavily, while the Polo brand, which has enjoyed a resurgence of late (thanks to the demand for logos and1990s nostalgia) was well represented, as was sport, ski and scholar chic.

But this fashion show – which featured more than 50 models – wasn’t so much about the clothes as the Ralph Lauren concept. The second part of the show summed it up best when models arrived with children (some basking in the limelight, others so tiny they were sleeping), stressing that Ralph Lauren is a brand with mass market, cross-generation appeal.

In a speech after the show, Oprah said the real reason they were all there was “because of you, Ralph. We’re here to celebrate you releasing our dreams and creating a sense of value that brings wholesomeness to glamour.”

The designer, 78, shows no signs of slowing down, outlining his ambitious growth plans to the New York Stock Exchange in June. In July, the Ralph Lauren Corp published first-quarter results, which revealed net income up 83.2% to $109m, while net revenue increased by 3.2% to $1.39m.

To close, Lauren took an emotional lap of honour, embracing his friends, family and famous attendees. “I don’t dream this big, but this is beyond my dreams tonight,” he said, before the guests departed – all still wearing their shoes.