Siddharth, who scripted the first century break in the competition, managed to win by 17 points towards the end after he compiled 147 to take initial lead.
Peter fought back strongly as he crafted a couple of close to century breaks to dismantle the early lead of Siddharth.
India's ace cueist and defending champion Pankaj Advani had a cakewalk victory over compatriot S Shankar Rao by 390 points.
In another match, England's Robert Hall trounced India's B Bhaskar 500-287 after he posted two back-to-back century breaks.
Bhaskar took an early lead over Hall by posting century break break of 118 points, but the English player bounced back by scripting two century breaks with 116 and 113 points, to keep the Indian out of the game.
Bhaskar, however, lost a few chances to bounce back, but could not post any big break further. He ultimately closed the match in his favour by breaking 61 points.
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Meanwhile, India's young billiards star Dhvaj Haria surprised sports enthusiasts by defeating former World No. 2 and former Asian Billiards Champion Alok Kumar.
Dhvaj, who has already made a mark at international level, registered a overwhelming victory by more than 300 points after four excellent breaks of 106, 88, 65 and 88 points.
Alok could not latch on to initial chances coming his way and struggled to get hold of the match, and eventually lost out to Dhvaj.
Pankaj missed a golden opportunity to score double century break when he ended it on 193 after he failed to pot a yellow in bottom pocket.
Rupesh had to score 285 in his last chance, but failed and in his next visit Pankaj scored the remaining 55 points to win his second match of the day.