Singhraj had contracted Covid-19 three months ago and was hospitalised for 15 days that had abruptly halted his training regime.
Mariyappan, who was the gold medalist at the 2016 Rio Paralympics, narrowly missed out on the Tokyo gold as he recorded a jump of 1.86 meters.
The 41-year-old athlete, who was injured during the 1971 Indo-Pakistan war, produced a best throw of 19.91m to finish third.
The Paralympics debutant recorded an absolutely phenomenal throw of 68.55m to seal the gold medal for India.
Jhajahria, already India's greatest Paralympian after winning gold in the 2004 and 2016 Games, pulled off a new personal best throw of 64.35m.
Vinod Kumar won a bronze medal in the Discus Throw T52 event, which was put on hold after a protest over his disability classification.
It is a different kind of feeling when para-athletes win medals for the country at Tokyo Paralympics
Vinod Kumar won bronze with a best throw of 19.91, which marked India's third medal in the ongoing Tokyo Paralympics.
Bhavina Patel rallied against odds to reach the final, but lost it to the Chinese legend Zhou Ying 0-3 to finish with a silver medal.
Bhavina Patel continued to script history as she became the first Indian to enter the final of a table tennis event in the Paralympics.