Poonawalla's striking look was created by Sabyasachi, worn with an ornate Schiaparelli Couture corset that curves over her head.
According to the label's Instagram, the sari "celebrates Indian craftsmanship", the gold handcrafted piece is "embroidered with silk floss thread and embellished with bevel beads, semi-precious stones, crystals, sequins and appliqued printed velvet".
The look was accessorised with custom Sabyasachi Fine Jewellery pieces.
Designer Sabyasachi Mukherjee wrote of his design: “For me the sari is a truly unique and versatile garment that owns its identity even as it transcends boundaries and geographies. Back when I was a young fashion student, I often wondered when I would see the sari at big global fashion events like the Met Gala.”
Celebrity stylist Anaita Shroff Adajania styled Poonawalla for the event, and her sari was draped by Dolly Jain.
On Instagram, Jain said she was "in awe of this Indian take on Gilded Glamour".
"To be able to witness such an iconic fashion-meets-art moment in New York, and be a small part of it feels truly surreal. Between the flowing drape of her bespoke embroidered gold Sabyasachi sari and the architectural lines of her armour-esque gold metallic Schiaparelli couture bustier, Natasha strikes a note that is both feminine yet strong, bold yet beautiful," Jain wrote.
This year, the Met Gala's Gilded Glamour theme honoured New York's 19th century golden age between 1870 and 1890, with full Regency-style dresses expected on the red carpet. Like Poonawalla, a host of the A-list names in attendance took the gilded theme literally, dressing in head-to-toe gold.
Moschino seemed to be the fashion house behind many of the golden looks — the label dressed Khloe Kardashian, Megan Thee Stallion, Michaela Jae Rodriguez and Ariana DeBose, who was co-ordinated with designer Jeremy Scott in a black and gold design.