Narwal and Singhraj overtook the Chinese duo of Xiaolong and Yang Chao in the fourth series of shots as the Chinese shooters faltered with 7.5 and 8.7 respectively.
Patel, who plays in a wheelchair, lost the opening game in a tight contest. But, she made a strong recovery, claiming the next two games to take a 2-1 lead.
The Paralympic Games will start on August 24 and will continue till September 5.
From a gathering of 400 physically challenged athletes from 23 countries at Rome in 1960 to 4,400 participants from 137 countries at Tokyo, the Paralympic Games have come a long way in the last 61 years.
A total of 54 athletes in nine disciplines including archery, athletics, badminton, swimming and weightlifting, among others will compete in Tokyo.