Siti Noor Iasah Mohamad Ariffin has qualified for the women's 400m final in the T20 (intellectual disability) category at the Paralympics Games in Rio de Janeiro.

In the heats at the Rio Olympic Stadium on Monday, Siti Noor Iasah, 27, won the second heat in a time of 58.96s, a new Asian Record.

"I actually did target to run below 60s, I was only aiming to get into the final. In my heat, I raced against the world No.1 runner (Barbara Niewiedzial from Poland).

"She (Barbara) is an experienced runner. I was in the front lane (lane eighth), so I did not see her as she was behind me ... as I was running, I was only concentrating on the finish line," she told Bernama through WhatsApp.

Niewiedzial clocked 59.20s to finish in third place, 0.04s behind Natalia Iezlovetska from Ukraine.

The world record in the women's 400m T20 of 57.78s belongs to Niewiedzial. She set the mark at the IPC World Athletics Championships in Doha, Qatar last year.

"As for the final, I have to be careful with the other runners. Maybe they did not go all out during the heats. I will give my best," Siti Noor Iasah said.

She bettered her own old Asian Record of 1:01.33s at the 2014 Asian Para Games in Incheon, South Korea.

Siti Noor Iasah then went on to rewrite that record as well at the IPC World Athletics Championships in Doha, Qatar last year, clocking 60.35s to pick up the bronze.

The T2 400m final will be held on Tuesday and will see the top eight from the two heats held competing.