Reigning Asian champion Anas finished the race in 45.31 seconds to improve on his own national record mark, while the bronze medallist of the event, Javon Francis delivered a season best with a timing of 45.11 seconds.
The gold medal went to Botswana's Isaac Makwala, who completed the race in 44.35, while a 45.09 effort fetched compatriot Baboloki Thebe a silver medal.
Meanwhile, in the women's 400m semi-finals, Hima posted a personal best of 51.53 seconds to improve on her previous best of 51.97 seconds to advance to the final.
She finished third in the semi-final 1. She reached the final on the basis of having the top-two timings among the competitors who didn't finish top-two in each of the three heats.