The junior paddler, who jumped a few places in this month's ranking to be world number 12, defeated her Malaysian rival 11-5, 9-11, 11-8, 11-9, 11-8.
It was her last chance to make the cut for YOG, having failed to seal her berth at Rades (Tunisia) and Bangkok (Thailand) despite reaching the semifinals in the latter. Thakkar had booked his YOG ticket in the Thailand capital last month.
In fact, Archana had a very good chance of making the final in Bangkok but she lost after leading 3-2 and 10-8 in sixth game to Hungarian Fanni Harasztovich. In Tunisia, she exited in the quarterfinals, losing to Singapore's Zhang Wanling 2-4.
The trip to Rarotonga was, indeed, a tiresome affair with long layovers making it a 36-hour journey.
The top-seeded Indian had a first-round bye but in the second round it was tough against the Philippines' Jannah Maryam Romeron, who not only went ahead with a 2-0 lead but also posed a lot of problems for Archana.
However, the determined Indian won the crucial third game with a minimal margin and the next on extended points to restore parity. From there, it was a confident Archana who thumped her rival from the Philippines to enter the semifinals with a 11-13, 8-11, 11-9, 13-11, 11-7, 11-3.
In the semifinals, it was an easy affair for the world No. 12 as she beat Iran's Mahshid Ashtari 11-2, 11-7, 11-7, 11-5 and in the final, a cautious Archana dropped just one game before overpowering her Malaysian opponent to seal her YOG berth.