In contrast, two-time Asian champion Yasin Merchant warmed up with a comfortable 3-0 win over Aditya Agrawal, that included a break of 75 in the opening frame, in another group match.
Chandra and Joshi gave the elite main draw a kickstart with the former surging to a surprise 2-1 lead after man-in-form Joshi snatched the second frame with a brilliant break of 82.
Joshi's vast experience came to the fore again when he fired another 59 in the crucial fourth frame to force the fifth frame.
In the decider, that could have gone either way, Chandra held on dearly to a narrow lead and took the match away with a sigh of relief.
Sethi also endured a strong challenge from host gymkhana's Kalyaniwala in another absorbing contest that went down to the wire.
After Kalyaniwala won the crucial fourth frame, Sethi fired a decisive break of 60 in the decider to seal the issue.
Manish Jain of West Bengal, Shakeel Ahmed and Faisal Khan of Railways, Abhimanyu Gandhi of Gujarat, Varun Kumar of Tamil Nadu and Pushpinder Singh of Delhi qualified for the elite phase along with Rafath Habib of Railways, who was a lucky loser in place of Hyderabad cueist Lucky Vatnani, who pulled out. (More) PTI SSR RSY PDS